CI: test all three target platforms

Author: ctrueden

.github/workflows/build.yml

@@ -12,15 +12,19 @@ on:
 
 jobs:
   build:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.os }}
+    strategy:
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+        python-version: ["3.10", "3.13"]
 
     steps:
     - uses: actions/checkout@v4
 
     - name: Set up Python
       uses: actions/setup-python@v5
       with:
-        python-version: "3.10"
+        python-version: ${{matrix.python-version}}
 
     - name: Set up Java
       uses: actions/setup-java@v4
@@ -34,9 +38,11 @@ jobs:
         python -m pip install uv
 
     - name: Run the tests
+      shell: bash
       run: |
         bin/test.sh
 
     - name: Lint the code
+      shell: bash
       run: |
         bin/lint.sh