deps(gha): 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/release.yml

@@ -92,7 +92,7 @@ jobs:
           platforms: ${{ matrix.config.platform }}
 
       - name: 🔽 Setup Docker Buildx
-        uses: docker/setup-buildx-action@v3 # https://github.com/docker/setup-buildx-action
+        uses: docker/setup-buildx-action@v4 # https://github.com/docker/setup-buildx-action
 
       # cpp-devbox:{debian_codename}-{{date}}                # only on scheduled builds
       # cpp-devbox:{debian_codename}-{{version}}             # only on git tag