Bumps [docker/setup-buildx-action](https://github.com/docker/setup-buildx-action) from 3 to 4.
- vLLM version: v0.18.0
- vLLM main:
8b6325758c
Signed-off-by: dependabot[bot] <support@github.com>
Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>