CI: run tests with Python version

The 3.11 testing uses 3.12 without this.

Author: pjonsson

.github/workflows/main.yml

@@ -48,4 +48,4 @@ jobs:
           python-version: ${{ matrix.python-version }}
 
       - name: Run tests
-        run: uv run pytest
+        run: uv run --python ${{ matrix.python-version }} pytest