run uv in github actions

.github/workflows/tests.yml

@@ -35,19 +35,24 @@ jobs:
           python-version: ${{ matrix.python-version }}
           architecture: x64
 
-      - name: Apply caching of dependencies
-        uses: actions/cache@v4.0.0
+      - name: Install uv
+        uses: astral-sh/setup-uv@v4
         with:
-          path: ~/.cache/pip
-          key: os=${{ matrix.os }}-python=${{ matrix.python-version }}-pip-${{ hashFiles('**/requirements-*.txt') }}
+          enable-cache: true
+          cache-dependency-glob: "requirements**.txt"
 
       - name: Install dependencies
         run: |
-          pip install -U pip setuptools wheel
-          pip install -r requirements.txt -r requirements/requirements-test.txt django~=${{ matrix.django-version }} cryptography~=${{ matrix.cryptography-version }} pydantic~=${{ matrix.pydantic-version }}
+          uv pip install --system -U setuptools wheel
+          uv pip install --system -r requirements.txt -r requirements/requirements-test.txt django~=${{ matrix.django-version }} cryptography~=${{ matrix.cryptography-version }} pydantic~=${{ matrix.pydantic-version }}
 
       - name: Initialize demo
         run: python dev.py init-demo
 
       - name: Run tests
         run: pytest -v --cov-report term-missing --durations=20
+
+      # Prune cache, see:
+      #   https://docs.astral.sh/uv/concepts/cache/#caching-in-continuous-integration
+      - name: Prune uv cache
+        run: uv cache prune --ci