build(deps): 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](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] <[email protected]>

.github/workflows/ci-docker.yml

@@ -301,7 +301,7 @@ jobs:
       - name: Build artifacts
         if: ${{ steps.prepare.outputs.artifacts == 'true' }}
         id: build_artifacts
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: ./
           file: ${{ matrix.dockerfile }}
@@ -323,7 +323,7 @@ jobs:
 
       - name: Build and push
         id: build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           context: ./
           file: ${{ matrix.dockerfile }}