build(deps): bump docker/build-push-action from 3 to 6

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 3 to 6.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@v3...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]>

Author: dependabot[bot]

.github/workflows/deploy-docker.yml

@@ -171,7 +171,7 @@ jobs:
 
             - name: "📦 Build + Push › Root"
               id: task_release_gh_push_root
-              uses: docker/build-push-action@v3
+              uses: docker/build-push-action@v6
               if: ( github.event_name == 'workflow_dispatch' && inputs.PRINT_ONLY == 'false' )
               with:
                   context: .
@@ -187,7 +187,7 @@ jobs:
 
             - name: "📦 Build + Push › PHP"
               id: task_release_gh_push_php
-              uses: docker/build-push-action@v3
+              uses: docker/build-push-action@v6
               if: ( github.event_name == 'workflow_dispatch' && inputs.PRINT_ONLY == 'false' )
               with:
                   context: .