ci: enable gha caching on docker/build-push-action

Author: buchdag

.github/workflows/build-publish.yml

@@ -85,6 +85,8 @@ jobs:
           push: true
           tags: ${{ steps.docker_meta.outputs.tags }}
           labels: ${{ steps.docker_meta.outputs.labels }}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max
 
       - name: Docker image digest
         run: echo ${{ steps.docker_build.outputs.digest }}