Add MacOs test runner

.github/workflows/test.yml

@@ -112,13 +112,22 @@ jobs:
             gcc: gcc-8
             python-version: '3.11'
 
+          # Test minimum and maximum Python version on Windows.
+          - os: macos-12
+            gcc: gcc
+            python-version: '3.8'
+          - os: macos-12
+            gcc: gcc
+            python-version: '3.11'
+
     steps:
       - uses: actions/checkout@v4
       - name: Setup environment
         run: |
           # Enable coverage for specific target configurations
           case "${{ matrix.os }}/${{ matrix.gcc }}/${{ matrix.python-version }}" in
             windows-2019/gcc-8/3.8)   USE_COVERAGE=true ;;
+            macos-12/gcc-11/3.9)      USE_COVERAGE=true ;;
             ubuntu-22.04/gcc-11/3.11) USE_COVERAGE=true ;;
             *)                        USE_COVERAGE=false ;;
           esac
@@ -135,20 +144,21 @@ jobs:
         if: ${{ startsWith(matrix.os,'windows-') }}
         run: |
           choco install ninja
-      - name: Install build commands and GCC (Linux)
+      - name: Install ninja and libxml2 (MacOs)
+        if: ${{ startsWith(matrix.os,'macos-') }}
+        run: |
+          brew update
+          brew install ninja
+          brew install libxml2
+      - name: Install build commands, GCC and libxml2 (Linux)
         if: ${{ startsWith(matrix.os,'ubuntu-') }}
         run: |
           sudo apt update
           sudo apt-get install -y \
             make \
             ninja-build \
             ${{ matrix.gcc }} \
-            $(echo ${{ matrix.gcc }} | sed -e 's/gcc/g\+\+/')
-          sudo apt-get clean
-      - name: Install libxml2
-        if: ${{ startsWith(matrix.os,'ubuntu-') }}
-        run: |
-          sudo apt-get install -y \
+            $(echo ${{ matrix.gcc }} | sed -e 's/gcc/g\+\+/') \
             libxml2-utils
           sudo apt-get clean
       - name: Set up Python ${{ matrix.python-version }}