Update actions/checkout digest to b4ffde6 (#65)

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

.github/workflows/maven-central.yml

@@ -20,7 +20,7 @@ jobs:
   publish:
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@8ade135a41bc03ea155e62e844d188df1ea18608 # v4
+      - uses: actions/checkout@b4ffde65f46336ab88eb53be808477a3936bae11 # v4
       - name: Set up Java
         uses: actions/setup-java@v3
         with: