test(aot): build with (MSBuild)TreatWarningsAsErrors to catch warnings (#5125)

* test(aot): build with MSBuildTreatWarningsAsErrors

Projects using MSBuildTreatWarningsAsErrors=true would fail to publish
with Native AOT due to warnings. Add a test to prevent such warnings
slipping in.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

* test(aot): fold warnings-as-errors into the main Aot test

Enable both TreatWarningsAsErrors and MSBuildTreatWarningsAsErrors in the
main Aot publish test (all platforms) and drop the separate Windows-only
MSBuildTreatWarningsAsErrors block. Portable PDBs make the original
Windows-only scoping unnecessary, and reusing the existing test avoids a
second publish while also exercising the resulting binary at runtime.

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: jpnurmi

integration-test/aot.Tests.ps1

@@ -52,8 +52,16 @@ Console.WriteLine("Hello, Sentry!");
     It 'Aot' {
         $rid = $env:RuntimeIdentifier
         $baseImage = $env:ContainerBaseImage
-        $publishArgs = @('-c', 'Release')
-        if ($rid) {
+        # To exclude specific warnings without disabling warnings-as-errors entirely, add:
+        #   '-p:WarningsNotAsErrors=CS####;IL####'        # compiler/analyzer warnings (CS, IL2###, IL3###)
+        #   '-p:MSBuildWarningsNotAsErrors=MSB####'       # MSBuild task warnings (MSB###)
+        $publishArgs = @(
+            '-c', 'Release',
+            '-p:TreatWarningsAsErrors=true',
+            '-p:MSBuildTreatWarningsAsErrors=true'
+        )
+        if ($rid)
+        {
             Write-Host "Environment RuntimeIdentifier: $rid"
             $publishArgs += @('-r', $rid)
         }