Remove the deprecated/unused dotnet-xunit dependency

[reyang]

I haven't looked into why this happened and nobody noticed this previously, just got the warning while doing local build.

The problem is that dotnet-xunit is a DotNetCliToolReference rather than PackageReference, so the version specified in

opentelemetry-dotnet/Directory.Packages.props

Line 39 in 2e57e2d

<PackageVersion Include="dotnet-xunit" Version="[2.3.1,3.0)" />

is not being used at all.

Also, the existing code has reference to DotNetXUnitCliVer while that variable is not even defined anywhere:

opentelemetry-dotnet/test/OpenTelemetry.Api.Tests/OpenTelemetry.Api.Tests.csproj

Line 31 in 2e57e2d

<DotNetCliToolReference Include="dotnet-xunit" Version="$(DotNetXUnitCliVer)" />

[reyang]

@CodeBlanch these are no longer needed I assume?

[codecov]

Codecov Report

Merging #4574 (095620b) into main (039556d) will increase coverage by 0.05%.
The diff coverage is n/a.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #4574      +/-   ##
==========================================
+ Coverage   85.13%   85.18%   +0.05%     
==========================================
  Files         320      320              
  Lines       12679    12679              
==========================================
+ Hits        10794    10801       +7     
+ Misses       1885     1878       -7     

see 4 files with indirect coverage changes

[utpilla]

Is adding DotNetCliToolReference required? I removed the <DotNetCliToolReference Include="dotnet-xunit" /> from the test projects and it still works (both on Visual Studio TestExplorer and dotnet test)

[reyang]

Is adding DotNetCliToolReference required? I removed the <DotNetCliToolReference Include="dotnet-xunit" /> from the test projects and it still works (both on Visual Studio TestExplorer and dotnet test)

Probably not needed on modern tools https://xunit.net/docs/nuget-packages.

dotnet-xunit	This package was retired as of 2.4 Beta 2. .NET Core users should use xunit.runner.visualstudio and the dotnet test command line.