build(deps): Bump docker/build-push-action

Bumps the dependencies group in /.github/workflows with 1 update: [docker/build-push-action](https://github.com/docker/build-push-action).


Updates `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
  dependency-group: dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/release.yaml

@@ -166,7 +166,7 @@ jobs:
                     echo "DOCKER_TEST_TAG=ghcr.io/humbugphp/php-scoper" >> $GITHUB_ENV
 
             -   name: Build and export to Docker
-                uses: docker/build-push-action@v5
+                uses: docker/build-push-action@v6
                 with:
                     context: .
                     file: ${{ env.DOCKERFILE }}
@@ -179,7 +179,7 @@ jobs:
 
             -   name: Build and push
                 if: github.event_name == 'release'
-                uses: docker/build-push-action@v5
+                uses: docker/build-push-action@v6
                 with:
                     context: .
                     file: ${{ env.DOCKERFILE }}