Bump docker/setup-buildx-action from 3 to 4

Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 3 to 4.
- [Release notes](https://github.com/docker/setup-buildx-action/releases)
- [Commits](docker/setup-buildx-action@v3...v4)

---
updated-dependencies:
- dependency-name: docker/setup-buildx-action
  dependency-version: '4'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

.github/workflows/docker-publish.yml

@@ -64,7 +64,7 @@ jobs:
       # Needed to make caching on GHA work: https://stackoverflow.com/a/73884678.
       # https://github.com/docker/setup-buildx-action
       - name: Setup Docker buildx
-        uses: docker/setup-buildx-action@v3
+        uses: docker/setup-buildx-action@v4
 
       # Log into the registry except on PRs.
       # https://github.com/docker/login-action