Enable parallel MSBuild build instances again.

.github/workflows/BuildBinaries.yml

@@ -23,7 +23,7 @@ jobs:
     - name: Clear local NuGet cache (workaround for failed restores on windows-latest)
       run: dotnet nuget locals all --clear
     - name: Build
-      run: MSBuild -binaryLogger:Output\BuildAllTargets.binlog BuildAllTargets.proj
+      run: MSBuild -binaryLogger:Output\BuildAllTargets.binlog -m BuildAllTargets.proj
     - name: Upload MSIX Bundle
       uses: actions/upload-artifact@v4
       with:

BuildAllTargets.cmd

@@ -18,6 +18,6 @@ popd
 call "%VisualStudioInstallDir%\VC\Auxiliary\Build\vcvarsall.bat" x86
 
 rem Build all targets
-MSBuild -binaryLogger:Output\BuildAllTargets.binlog BuildAllTargets.proj
+MSBuild -binaryLogger:Output\BuildAllTargets.binlog -m BuildAllTargets.proj
 
 @endlocal