Solution does not build on Apple Silicon (M1)

[TylerHelmuth]

Bug Report

Symptom

Latest from main is unable to build on an Apple M1.

What is the expected behavior?

That new contributors on Apple M1 computers would be able to build the solution

What is the actual behavior?

The build fails specifically around Grpc/Protobuf.

Build FAILED.

/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/src/OpenTelemetry.Exporter.OpenTelemetryProtocol/OpenTelemetry.Exporter.OpenTelemetryProtocol.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.27.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/examples/GrpcService/Examples.GrpcService.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.27.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/examples/GrpcService/Examples.GrpcService.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.27.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/examples/GrpcService/Examples.GrpcService.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Google.Protobuf.Tools cannot determine host OS and CPU. [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : Use environment variables PROTOBUF_TOOLS_OS={linux|macosx|windows} and PROTOBUF_TOOLS_CPU={x86|x64} to try the closest match to your system. [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
/Users/thelmuth/.nuget/packages/grpc.tools/2.25.0/build/_protobuf/Google.Protobuf.Tools.targets(84,5): error : You may also set PROTOBUF_PROTOC to specify full path to the host-provided compiler (v3.5+ is required). [/Users/thelmuth/Projects/opentelemetry-dotnet/test/OpenTelemetry.Instrumentation.Grpc.Tests/OpenTelemetry.Instrumentation.Grpc.Tests.csproj]
    0 Warning(s)
    7 Error(s)

Reproduce

On an M1 mac:

1. download latest from main
2. run dotnet build
3. Observe build fails.

Additional Context

I have already solved this problem by updating several Grpc packages. Will submit a PR for this issue shortly.