Enable OpenTelemetry for Desktop target in xUnit tests (dotnet#18233)

Author: majocha

tests/FSharp.Test.Utilities/CompilerAssert.fs

@@ -59,8 +59,6 @@ module AssemblyResolver =
             match found() with
             | None -> Unchecked.defaultof<Assembly>
             | Some name -> Assembly.Load(name) )
-
-    do addResolver()
 #endif
 
 type ExecutionOutcome = 

tests/FSharp.Test.Utilities/FSharp.Test.Utilities.fsproj

@@ -33,7 +33,6 @@
     <None Include="ScriptingShims.fsx" />
     <Compile Include="TestConsole.fs" />
     <Compile Include="TestFramework.fs" />
-    <Compile Include="XunitHelpers.fs" />
     <Compile Include="ILChecker.fs" />
     <Compile Include="Utilities.fs" />
     <Compile Include="CompilerAssert.fs" />
@@ -46,6 +45,7 @@
     <Compile Include="FileInlineDataAttribute.fs" />
     <Compile Include="ReflectionHelper.fs" />
     <Compile Include="SurfaceArea.fs" />
+    <Compile Include="XunitHelpers.fs" />
   </ItemGroup>
 
   <ItemGroup>

tests/FSharp.Test.Utilities/XunitHelpers.fs

@@ -31,6 +31,9 @@ type FSharpXunitFramework(sink: IMessageSink) =
         // This gets executed once per test assembly.
         MessageSink.sinkWriter |> ignore
         TestConsole.install()
+#if !NETCOREAPP
+        AssemblyResolver.addResolver ()
+#endif
 
     interface IDisposable with
         member _.Dispose() =
@@ -148,24 +151,23 @@ type FSharpXunitFramework(sink: IMessageSink) =
         log "FSharpXunitFramework with XUNIT_EXTRAS installing TestConsole redirection"
         TestConsole.install()
 
-// TODO: Currently does not work with Desktop .NET Framework. Upcoming OpenTelemetry 1.11.0 may change it.
-#if NETCOREAPP
+#if !NETCOREAPP
+        AssemblyResolver.addResolver ()
+#endif
+
     let traceProvider =
         Sdk.CreateTracerProviderBuilder()
                 .AddSource(ActivityNames.FscSourceName)
                 .SetResourceBuilder(
                     ResourceBuilder.CreateDefault().AddService(serviceName="F#", serviceVersion = "1.0.0"))
                 .AddOtlpExporter()
                 .Build()
-#endif
 
     interface IDisposable with
         member _.Dispose() =
             cleanUpTemporaryDirectoryOfThisTestRun ()
-#if NETCOREAPP
             traceProvider.ForceFlush() |> ignore
             traceProvider.Dispose()
-#endif
             base.Dispose()        
 
     override this.CreateDiscoverer (assemblyInfo) =