ci(deps): bump docker/build-push-action from 5 to 6

Bumps docker/build-push-action from 5 to 6 with build summary support and enhanced attestation handling.

Author: dependabot[bot]

.github/workflows/docker-build-dockerhub.yml

@@ -81,7 +81,7 @@ jobs:
           password: ${{ secrets.DOCKERHUB_TOKEN }}
 
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile