support caching of dependencies

.github/workflows/ci.yml

@@ -19,17 +19,28 @@ jobs:
           # Important: Fetch the correct commit for pull_request_target
           ref: ${{ github.event.pull_request.head.sha }} # For pull_request_target
 
-      - name: Set up Python v3.13
+      - name: Set up Python
         uses: actions/setup-python@v5
         with:
           python-version: "3.13"
+
+      - name: Cache pip
+        uses: actions/cache@v4
+        with:
+          path: ~/.cache/pip
+          key: ${{ runner.os }}-pip-${{ hashFiles('**/requirements*.txt') }}
+          restore-keys: |
+            ${{ runner.os }}-pip-
+
       - name: Install dependencies
         run: |
           python -m pip install --upgrade pip
           pip install -r requirements-dev.txt
+
       - name: Run flake8
         run: |
           flake8 --config=.flake8
+
       - name: Run pytest
         run: |
           pytest -c pytest.ini