actions: install a python and let's hope the rest will work

.forgejo/workflows/prek.yaml

@@ -8,9 +8,15 @@ jobs:
     runs-on: docker
     steps:
       - uses: https://code.forgejo.org/actions/checkout@v6
-      - uses: https://github.com/j178/prek-action@v1
+      - uses: https://code.forgejo.org/actions/setup-python@v6
         with:
-          install-only: true
+          python-version: "3.14"
+          cache: "pip"
+          cache-dependency-path: |
+            pyproject.toml
+            requirements*.txt
       - run: |
-          echo "we needs us a python interpreter"
-          echo "do we have `uv`?"
+          python -m venv venv
+          . venv/bin/activate
+          pip install --disable-pip-version-check --require-virtualenv --quiet uv
+          uv run --active pytest tests.py