Bump docker/setup-buildx-action from 2.8.0 to 2.9.0 (#828)

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 2.8.0 to 2.9.0.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](docker/setup-buildx-action@16c0bc4...2a1a44a)

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

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

Author: dependabot[bot]

.github/workflows/ci.yml

@@ -159,7 +159,7 @@ jobs:
           go-version-file: go.mod
 
       - name: Docker Buildx
-        uses: docker/setup-buildx-action@16c0bc4a6e6ada2cfd8afd41d22d95379cf7c32a # v2.8.0
+        uses: docker/setup-buildx-action@2a1a44ac4aa01993040736bd95bb470da1a38365 # v2.9.0
 
       - name: Docker meta
         id: meta
@@ -246,7 +246,7 @@ jobs:
           key: nginx-kubernetes-gateway-${{ github.run_id }}-${{ github.run_number }}
 
       - name: Docker Buildx
-        uses: docker/setup-buildx-action@16c0bc4a6e6ada2cfd8afd41d22d95379cf7c32a # v2.8.0
+        uses: docker/setup-buildx-action@2a1a44ac4aa01993040736bd95bb470da1a38365 # v2.9.0
 
       - name: Setup QEMU
         uses: docker/setup-qemu-action@2b82ce82d56a2a04d2637cd93a637ae1b359c0a7 # v2.2.0