Bump docker/build-push-action from 5 to 6 in the ci group

Bumps the ci group 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: ci
...

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

Author: dependabot[bot]

.github/workflows/build.yml

@@ -40,7 +40,7 @@ jobs:
       - name: Set VERSION
         run: echo "VERSION=${GITHUB_REF#refs/*/}" >> $GITHUB_ENV
       - name: Build
-        uses: docker/build-push-action@v5
+        uses: docker/build-push-action@v6
         with:
           builder: ${{ steps.buildx.outputs.name }}
           platforms: linux/amd64,linux/arm64