Update docker/build-push-action action to v6

Author: renovate[bot]

.github/workflows/release.yml

@@ -63,7 +63,7 @@ jobs:
         run: echo "BUILD_DATE=$(date -u +'%Y-%m-%dT%H:%M:%SZ')" >> ${GITHUB_ENV}
 
       - name: Build & Push Docker Image
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile