ci: update buildx to latest

Signed-off-by: CrazyMax <[email protected]>

Author: crazy-max

.github/workflows/ci.yml

@@ -24,7 +24,7 @@ on:
   pull_request:
 
 env:
-  BUILDX_VERSION: v0.12.0-rc1
+  BUILDX_VERSION: latest
   BUILDKIT_IMAGE: moby/buildkit:buildx-stable-1
 
 jobs: