chore: update actions/cache action to v4.2.1

Author: renovate-bot

.github/workflows/docker-parallel-multiarch-build.yml

@@ -140,7 +140,7 @@ jobs:
           cat $GITHUB_OUTPUT
 
       - name: Setup buildkit mount cache
-        uses: actions/cache@1bd1e32a3bdc45362d1e726936510720a7c30a57 # v4.2.0
+        uses: actions/cache@0c907a75c2c80ebcb7f088228285e798b750cf8f # v4.2.1
         if: steps.vars.outputs.cache-paths
         with:
           path: |