Bump docker/setup-buildx-action from 3.7.1 to 3.8.0

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 3.7.1 to 3.8.0.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](docker/setup-buildx-action@c47758b...6524bf6)

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

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

.github/workflows/testbuild.yml

@@ -38,7 +38,7 @@ jobs:
       - name: Check out code
         uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v3
       - name: Set up Docker Buildx
-        uses: docker/setup-buildx-action@c47758b77c9736f4b2ef4073d4d51994fabfe349 # v3
+        uses: docker/setup-buildx-action@6524bf65af31da8d45b59e8c27de4bd072b392f5 # v3
       - name: Build Docker image
         uses: docker/build-push-action@48aba3b46d1b1fec4febb7c5d0c644b249a11355 # v6
         with: