🔧 Template: Add tests job to CI workflow

We choose to only test against the min and max Python versions supported, and run the
provided Hatch script for running the tests.

Note that we pin `click==8.2.1` because `8.3.0` breaks Hatch, and `8.2.2` has been
yanked.

Author: mbercx

template/.github/workflows/.ci.yml

@@ -18,3 +18,17 @@ jobs:
 
       - name: Run pre-commit
         run: hatch run precommit:run
+
+  tests:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.9', '3.13']
+
+    steps:
+      - uses: actions/checkout@v4
+      - uses: actions/setup-python@v5
+        with:
+          python-version: ${{ matrix.python-version }}
+      - run: pip install click==8.2.1 hatch
+      - run: hatch run test:run