CompilationWithAnalyzer.GetAnalyzerDiagnosticsAsync returns 0 diagnostics even though the analyzers do run & report

[ujjwalchadha]

Version Used: Microsoft.CodeAnalysis.Analyzers 3.3.2

Steps to Reproduce:

1. Create a UWP Project
2. Using a separate project that uses Microsoft.CodeAnalysis.Analyzers and at least one new analyzer that can provide some diagnostic on the UWP project, call CompilationWithAnalyzer.GetAnalyzerDiagnosticsAsync(token)

Expected Behavior: The call to function returns 1 diagnostic

Actual Behavior: The call to function returns 0 diagnostic, even though the analyzer does run an does create the diagnostic

BUT Adding TFM = net6-windowsXXX and Sdk="Microsoft.NET.Sdk" to the UWP project csproj (although invalid for UWP) fixes the issue where it returns the correct diagnostics that are reported.

This is happening at this line of the .NET Upgrade Assistant Project. Running our analyzers on a UWP project gives 0 diagnostic results while running this on a Net6 project gives the correct expected results.