Add pip caching to lint CI

Signed-off-by: Derek Nola <[email protected]>

.github/workflows/lint.yml

@@ -20,6 +20,7 @@ jobs:
         uses: actions/setup-python@v2
         with:
           python-version: '3.x'
+          cache: 'pip'
 
       - name: Install test dependencies.
         run: pip3 install yamllint ansible-lint ansible