github: [skip ci]: bump docker/build-push-action from 5 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 5 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](https://github.com/docker/build-push-action/compare/v5...v6)

---
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/github-packages.yml

@@ -59,7 +59,7 @@ jobs:
         env:
           DOCKER_METADATA_ANNOTATIONS_LEVELS: manifest,index
       - name: Build and push
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: "{{defaultContext}}:${{ matrix.dist }}"
           # we need to build for arm64 first at kamailio.sipwise.com