build(deps): bump docker/setup-buildx-action from 1 to 2

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 1 to 2.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](docker/setup-buildx-action@v1...v2)

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

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

.github/workflows/staging-build.yaml

@@ -14,7 +14,7 @@ jobs:
       - name: check out code
         uses: actions/checkout@v2
       - name: set up docker buildx
-        uses: docker/setup-buildx-action@v1
+        uses: docker/setup-buildx-action@v2
       - name: cache docker layers
         uses: actions/[email protected]
         with: