Bump docker/build-push-action from 6.5.0 to 6.6.1 (#338)

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.5.0 to 6.6.1.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@5176d81...16ebe77)

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

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -68,7 +68,7 @@ jobs:
         uses: docker/setup-buildx-action@988b5a0280414f521da01fcc63a27aeeb4b104db # v3.6.1
 
       - name: Build Plus Docker Image
-        uses: docker/build-push-action@5176d81f87c23d6fc96624dfdbcd9f3830bbe445 # v6.5.0
+        uses: docker/build-push-action@16ebe778df0e7752d2cfcbd924afdbbd89c1a755 # v6.6.1
         with:
           file: docker/Dockerfile
           tags: nginx-plus