Bump docker/build-push-action from 5 to 6 (#160)

Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/ci.yaml

@@ -263,7 +263,7 @@ jobs:
           password: ${{ github.token }}
 
       - name: Build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           file: Dockerfile.gh-actions
           context: ctx