chore(deps): pin actions/checkout action to b4ffde6 (#235)

Signed-off-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>
Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

.github/workflows/nightly.yaml

@@ -20,7 +20,7 @@ jobs:
     env:
       CONTAINER_ENGINE: podman
     steps:
-      - uses: actions/checkout@v4 # default branch will be checked out by default on scheduled workflows
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4 # default branch will be checked out by default on scheduled workflows
         with:
           fetch-depth: 0