Fix Python setup in CI

.gitea/workflows/tests.yml

@@ -8,11 +8,17 @@ jobs:
     runs-on: bs-node
     steps:
       - uses: https://github.com/actions/checkout@v4
-      - uses: https://github.com/actions/setup-python@v5
+      # uv supplies standalone Python builds for the Debian job container.
+      - uses: https://github.com/astral-sh/setup-uv@v6
         with:
-          python-version: '3.13'
-          cache: pip
+          version: '0.9.6'
+          enable-cache: false
+          github-token: ''
+      - name: Create Python environment
+        run: uv venv --python 3.13 --seed .venv
       - name: Install test dependencies
-        run: python -m pip install -r requirements-test.txt
+        run: uv pip install --python .venv/bin/python -r requirements-test.txt
       - name: Run checks
-        run: sh scripts/check.sh
+        run: |
+          . .venv/bin/activate
+          sh scripts/check.sh