build(deps): bump docker/setup-buildx-action in the github-actions group

Bumps the github-actions group with 1 update: [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action).


Updates `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@e468171...8d2750c)

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

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

Author: dependabot[bot]

.github/workflows/flex-build-push.yml

@@ -40,7 +40,7 @@ jobs:
             type=semver,pattern={{version}}
             type=semver,pattern={{major}}.{{minor}}
             type=semver,pattern={{major}}
-      - uses: docker/setup-buildx-action@e468171a9de216ec08956ac3ada2f0791b6bd435 # v3.11.1
+      - uses: docker/setup-buildx-action@8d2750c68a42422c14e847fe6c8ac0403b4cbd6f # v3.12.0
       - uses: docker/login-action@5e57cd118135c172c3672efd75eb46360885c0ef # v3.6.0
         with:
           registry: ${{ env.REGISTRY }}