ci: bump docker/build-push-action from 6.15.0 to 6.16.0

Bumps [docker/build-push-action](https://github.com/docker/build-push-action) from 6.15.0 to 6.16.0.
- [Release notes](https://github.com/docker/build-push-action/releases)
- [Commits](docker/build-push-action@471d1dc...14487ce)

---
updated-dependencies:
- dependency-name: docker/build-push-action
  dependency-version: 6.16.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

.github/workflows/build-xemu-win64-toolchain.yml

@@ -44,7 +44,7 @@ jobs:
           username: ${{ github.actor }}
           password: ${{ secrets.GITHUB_TOKEN }}
       - name: Build and push image
-        uses: docker/build-push-action@471d1dc4e07e5cdedd4c2171150001c434f0b7a4 # v5
+        uses: docker/build-push-action@14487ce63c7a62a4a324b0bfb37086795e31c6c1 # v5
         with:
           context: ubuntu-win64-cross
           push: ${{ github.event_name == 'push' && github.ref == 'refs/heads/master' }}