[libc++] Update the docker-compose file for actions CI

Author: ldionne

.github/workflows/libcxx-build-containers.yml

@@ -54,12 +54,12 @@ jobs:
       run: |
         docker compose push actions-builder
       env:
-        TAG: libcxx-linux-builder:${{ github.sha }}
+        TAG: ${{ github.sha }}
 
     # - name: Push the Android builder image
     #   if: github.event_name == 'push'
     #   working-directory: libcxx/utils/ci
     #   run: |
     #     docker compose push android-buildkite-builder
     #   env:
-    #     TAG: libcxx-android-builder:${{ github.sha }}
+    #     TAG: ${{ github.sha }}

libcxx/utils/ci/docker-compose.yml

@@ -1,30 +1,20 @@
-version: '3.7'
-
 x-versions: &compiler_versions
   GCC_LATEST_VERSION: 14
   LLVM_HEAD_VERSION: 20
 
 services:
-  buildkite-builder:
-    image: ghcr.io/libcxx/buildkite-builder:${TAG:-latest}
-    build:
-      context: .
-      dockerfile: Dockerfile
-      target: buildkite-builder
-      args:
-        BASE_IMAGE: ubuntu:noble
-        <<: *compiler_versions
   actions-builder:
-    image: ghcr.io/libcxx/actions-builder:${TAG:-latest}
+    image: ghcr.io/llvm/libcxx-linux-builder:${TAG}
     build:
       context: .
       dockerfile: Dockerfile
       target: actions-builder
       args:
         BASE_IMAGE: ghcr.io/actions/actions-runner:2.319.1
         <<: *compiler_versions
+
   android-buildkite-builder:
-    image: ghcr.io/libcxx/android-buildkite-builder:${TAG:-latest}
+    image: ghcr.io/llvm/libcxx-android-builder:${TAG}
     build:
       context: .
       dockerfile: Dockerfile