chore(deps): update actions/setup-python action to v4

| datasource  | package              | from | to |
| ----------- | -------------------- | ---- | -- |
| github-tags | actions/setup-python | v2   | v4 |

.github/workflows/ci.yml

@@ -28,7 +28,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@v2
-      - uses: actions/setup-python@v2
+      - uses: actions/setup-python@v4
         with:
           python-version: "3.9"
       - uses: actions/cache@v2