Test caching of deps in CI

.github/workflows/build.yml

@@ -102,6 +102,9 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            requirements.txt
 
       - name: Set up Python dependencies
         run: pip install --upgrade build twine

.github/workflows/documentation.yml

@@ -53,6 +53,9 @@ jobs:
         with:
           python-version: ${{ env.PYTHON_VERSION }}
           cache: pip
+          cache-dependency-path: |
+            pyproject.toml
+            requirements.txt
 
       - name: Set up build cache
         uses: actions/cache/restore@v3