Unset MicrosoftNetCompilersToolsetVersion (#45881)

* Unset MicrosoftNetCompilersToolsetVersion

* Update ClientResultsManager.cs

Author: wtgodbe

eng/Versions.props

@@ -159,9 +159,6 @@
     <MicrosoftNETCoreAppRuntimeVersion>$(MicrosoftNETCoreAppRuntimewinx64Version)</MicrosoftNETCoreAppRuntimeVersion>
   </PropertyGroup>
   <PropertyGroup Label="Manual">
-    <!-- Bumping the Roslyn version used in order to ingest the new runtime source generators -->
-    <UsingToolMicrosoftNetCompilers>true</UsingToolMicrosoftNetCompilers>
-    <MicrosoftNetCompilersToolsetVersion>4.5.0-1.22517.9</MicrosoftNetCompilersToolsetVersion>
     <!-- DiagnosticAdapter package pinned temporarily (??) until migrated/deprecated -->
     <!-- This is the latest version found in dotnet-public. -->
     <MicrosoftExtensionsDiagnosticAdapterVersion>5.0.0-preview.3.20215.2</MicrosoftExtensionsDiagnosticAdapterVersion>

src/SignalR/common/Shared/ClientResultsManager.cs

@@ -23,7 +23,7 @@ public Task<T> AddInvocation<T>(string connectionId, string invocationId, Cancel
             var tcs = (TaskCompletionSourceWithCancellation<T>)state;
             if (completionMessage.HasResult)
             {
-                tcs.SetResult((T)completionMessage.Result);
+                tcs.SetResult((T)completionMessage.Result!);
             }
             else
             {