ci(actionlint): pin checkout action to hash

Author: cardoso

.github/workflows/actionlint.yml

@@ -5,7 +5,7 @@ jobs:
   actionlint:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v6
+      - uses: actions/checkout@de0fac2e4500dabe0009e67214ff5f5447ce83dd # v6.0.2
       - name: Check workflow files
         run: |
           echo "::add-matcher::.github/actionlint-matcher.json"