ci: Re-enable ARM64 builds again

Author: Eta0

.github/workflows/build.yml

@@ -34,7 +34,7 @@ jobs:
   build:
     name: Build Images
     runs-on: [ cw ]
-    container: 'ghcr.io/coreweave/github-actions-images/github-base-runner:v1.6.0'
+    container: 'ghcr.io/coreweave/github-actions-images/github-base-runner:v1.9.0'
     defaults:
       run:
         shell: bash
@@ -109,7 +109,7 @@ jobs:
           labels: ${{ steps.meta.outputs.labels }}
           cache-from: type=registry,ref=${{ env.REGISTRY }}/buildcache:${{ env.CACHE_KEY || inputs.image-name }}
           cache-to: type=registry,ref=${{ env.REGISTRY }}/buildcache:${{ env.CACHE_KEY || inputs.image-name }},mode=max
-          platforms: linux/amd64
+          platforms: linux/amd64,linux/arm64
       - name: Clear registry credentials
         if: always()
         run: |