Re-added WinRT support until we're sure that it's no longer being used

.github/workflows/msvc.yml

@@ -19,6 +19,8 @@ jobs:
         - { name: Windows (clang-cl x86), flags: -T ClangCL -A Win32 }
         - { name: Windows (ARM),          flags: -A ARM }
         - { name: Windows (ARM64),        flags: -A ARM64 }
+        - { name: UWP (x64),              flags: -A x64 -DCMAKE_SYSTEM_NAME=WindowsStore -DCMAKE_SYSTEM_VERSION="10.0" -DSDL_TESTS=OFF, nowerror: true,
+            project: VisualC-WinRT/SDL-UWP.sln, projectflags: '/p:Platform=x64 /p:WindowsTargetPlatformVersion=10.0.17763.0' }
 
     steps:
     - uses: actions/checkout@v3
@@ -57,6 +59,7 @@ jobs:
         echo "SDL3_DIR=$Env:GITHUB_WORKSPACE/prefix" >> $Env:GITHUB_ENV
         cmake --install build/
     - name: Verify CMake configuration files
+      if: ${{ !contains(matrix.platform.name, 'UWP') }}  # FIXME: cmake/test/CMakeLists.txt should support UWP
       run: |
         cmake -S cmake/test -B cmake_config_build `
           -DCMAKE_PREFIX_PATH=${{ env.SDL3_DIR }} `