build(deps): bump docker/build-push-action from 5 to 6 (#406)

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](docker/build-push-action@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] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

.github/workflows/build-docker.yml

@@ -60,7 +60,7 @@ jobs:
       - name: Build and push (release)
         id: docker_build_release
         if: github.event_name == 'release'
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile
@@ -85,7 +85,7 @@ jobs:
       - name: Build and push (master)
         id: docker_build_master
         if: github.event_name != 'release'
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: .
           file: Dockerfile