Merge pull request #41 from yegor256/renovate/actions-checkout-4.x

Update actions/checkout action to v4

.github/workflows/docker.yml

@@ -10,6 +10,6 @@ jobs:
   docker:
     runs-on: ubuntu-20.04
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - run: docker build . -t home
       - run: docker run --rm home echo Hello