build(deps): bump docker/build-push-action from 5.1.0 to 6.9.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5.1.0 to 6.9.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v5.1.0...v6.9.0)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <[email protected]>

.github/workflows/release.yaml

@@ -36,7 +36,7 @@ jobs:
           images: cmidair/doc-bot-litellm
 
       - name: Build and push Docker image
-        uses: docker/build-push-action@v5.1.0
+        uses: docker/build-push-action@v6.9.0
         with:
           platforms: linux/amd64,linux/arm64
           context: ./litellm