Stop supporting .NET 5 after 8th May 2022

[reyang]

.NET 5.0 will reach end of support on May 08, 2022.
https://devblogs.microsoft.com/dotnet/dotnet-5-end-of-support-update/

Should we remove .NET 5.0 support?

[Oberon00]

I think it will still be supported e.g. in Azure Functions, won't it? https://docs.microsoft.com/en-us/azure/azure-functions/functions-versions?tabs=in-process%2Cv4&pivots=programming-language-csharp#languages

[cijothomas]

I think it will still be supported e.g. in Azure Functions, won't it? https://docs.microsoft.com/en-us/azure/azure-functions/functions-versions?tabs=in-process%2Cv4&pivots=programming-language-csharp#languages

Azure follows different lifecycles I think. It should not affect this repo.

Regd. .NET5 - there aren't many .NET 5 specific code, so it'd be mostly removing test targets. (saves some CI time.).

[reyang]

Azure follows different lifecycles I think. It should not affect this repo.

OpenTelemetry .NET lifecycle is not tight to any cloud providers / vendors. I think in general we try to align with .NET runtime. https://github.com/open-telemetry/opentelemetry-dotnet#supported-net-versions