Update native-build.yml

Author: wieslawsoltes

.github/workflows/native-build.yml

@@ -31,6 +31,10 @@ on:
         description: .NET version to install.
         type: string
         default: 8.0.x
+      install_gtk:
+        description: Install GTK and related GUI dependencies (macOS only).
+        type: boolean
+        default: false
     outputs:
       rid:
         description: Runtime identifier generated by the native build.
@@ -60,12 +64,19 @@ jobs:
         shell: bash
 
       - name: Install dependencies (macOS)
-        if: startsWith(inputs.runner, 'macos')
+        if: startsWith(inputs.runner, 'macos') && inputs.install_gtk == true
         run: |
           brew update
           brew install gtk+3 ninja clang-format
         shell: bash
 
+      - name: Ensure Ninja (macOS)
+        if: startsWith(inputs.runner, 'macos')
+        run: |
+          if ! command -v ninja >/dev/null 2>&1; then
+            brew install ninja
+          fi
+
       - name: Install dependencies (Windows)
         if: startsWith(inputs.runner, 'windows')
         run: choco install ninja -y