ci: update docker/build-push-action action to v6 (#5)

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

Author: renovate[bot]

.github/workflows/release.yaml

@@ -38,7 +38,7 @@ jobs:
           password: ${{ github.token }}
 
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           push: true