build(deps): bump docker/setup-buildx-action from 2.1.0 to 2.2.1

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 2.1.0 to 2.2.1.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](https://github.com/docker/setup-buildx-action/compare/v2.1.0...v2.2.1)

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

Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index e00120a..a5a57ee 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -15,7 +15,7 @@
           files: images/prometheus-ethtool-exporter/*
       - uses: docker/setup-qemu-action@v2.1.0
         if: steps.changed-files.outputs.any_changed == 'true'
-      - uses: docker/setup-buildx-action@v2.1.0
+      - uses: docker/setup-buildx-action@v2.2.1
         if: steps.changed-files.outputs.any_changed == 'true'
       - run: echo PROJECT_REF=$(cat images/prometheus-ethtool-exporter/ref) >> $GITHUB_ENV
         if: steps.changed-files.outputs.any_changed == 'true'