Bump Microsoft.NET.Test.Sdk from 16.11.0 to 17.0.0 in /Rx.NET/Source

Bumps [Microsoft.NET.Test.Sdk](https://github.com/microsoft/vstest) from 16.11.0 to 17.0.0.
- [Release notes](https://github.com/microsoft/vstest/releases)
- [Commits](microsoft/vstest@v16.11.0...v17.0.0)

---
updated-dependencies:
- dependency-name: Microsoft.NET.Test.Sdk
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Rx.NET/Source/tests/Tests.System.Reactive.ApiApprovals/Tests.System.Reactive.ApiApprovals.csproj

@@ -25,7 +25,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />
     <PackageReference Include="Verify.Xunit" Version="11.24.0" />
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />

Rx.NET/Source/tests/Tests.System.Reactive/Tests.System.Reactive.csproj

@@ -16,7 +16,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="16.11.0" />    
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.0.0" />    
     <PackageReference Include="xunit" Version="2.4.1" />
     <PackageReference Include="xunit.runner.visualstudio" Version="2.4.3" />
     <ProjectReference Include="..\..\src\System.Reactive\System.Reactive.csproj" />