Bump docker/setup-buildx-action from 3.11.1 to 3.12.0 (#761)

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 3.11.1 to 3.12.0.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](docker/setup-buildx-action@v3.11.1...v3.12.0)

---
updated-dependencies:
- dependency-name: docker/setup-buildx-action
  dependency-version: 3.12.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

.github/workflows/mpi-operator-docker-image-publish.yml

@@ -46,7 +46,7 @@ jobs:
         uses: docker/[email protected]
 
       - name: Docker Setup Buildx
-        uses: docker/setup-buildx-action@v3.11.1
+        uses: docker/setup-buildx-action@v3.12.0
 
       - name: Build and push
         uses: docker/build-push-action@v6