Pin (and upgrade) immutable-eligible action actions/checkout to their semantic versions

Author: mrecachinas

.github/workflows/docker-ci.yml

@@ -14,6 +14,6 @@ jobs:
   build:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+      - uses: actions/checkout@4.2.2
       - name: Build the Docker image
         run: docker build . --file Dockerfile --platform linux/amd64