Install glslang for Windows CI

Install glslang with validator tools and optimizer support, add it to PATH, and verify it before configuring the Windows build.

.github/workflows/build.yml

@@ -22,6 +22,14 @@ jobs:
       - name: Setup Ninja
         uses: seanmiddleditch/gha-setup-ninja@v5
 
+      - name: Install glslang
+        shell: pwsh
+        run: |
+          $vcpkgRoot = Split-Path (Get-Command vcpkg).Source
+          vcpkg install glslang[tools,opt]:x64-windows
+          "$vcpkgRoot\installed\x64-windows\tools\glslang" |
+            Out-File -FilePath $env:GITHUB_PATH -Encoding utf8 -Append
+
       - name: Install Qt 6.10.3
         uses: jurplel/install-qt-action@v4
         with:
@@ -38,6 +46,7 @@ jobs:
           cmake --version
           ninja --version
           clang-cl --version
+          glslangValidator --version
           echo Qt6_DIR=%Qt6_DIR%
 
       - name: Configure