Try MacOS and MS Windows CI testing (#3)

Add MacOS  CI testing

Author: rocky

.github/workflows/macos.yml

@@ -0,0 +1,42 @@
+name: Mathics3 Module PyICU (macOS)
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: '**'
+
+jobs:
+  build:
+    runs-on: macos-latest
+    strategy:
+      matrix:
+        os: [macOS]
+        python-version: ['3.12', '3.13']
+    steps:
+    - uses: actions/checkout@v4
+    - name: Set up Python ${{ matrix.python-version }}
+      uses: actions/setup-python@v5
+      with:
+        python-version: ${{ matrix.python-version }}
+    - name: Set ICU version
+      run: |
+        echo "PKG_CONFIG_PATH=$(brew --prefix icu4c)/lib/pkgconfig" >> $GITHUB_ENV
+    - name: Install dependencies
+      run: |
+        brew install llvm
+        python -m pip install --upgrade pip
+        python -m pip install pytest
+        # # Go over and comment out stuff when next Mathics core and Mathics-scanner are released
+        # python -m pip install -e git+https://github.com/Mathics3/mathics-scanner#egg=Mathics-Scanner[full]
+        # git clone https://github.com/Mathics3/mathics-core
+        # (cd mathics-core && pip3 install -e .[full])
+        # (cd mathics-core && bash ./admin-tools/make-JSON-tables.sh)
+        # python -m pip install -e git+https://github.com/Mathics3/Mathics3-Module-Base#egg=Mathics3-Module-Base
+    - name: Install Mathic3 PyICU Module
+      run: |
+        python -m pip install Mathics3 PyICU
+        python -m pip install --no-build-isolation -e .
+    - name: Test Mathics3 Module PyICU
+      run: |
+        make check