ensure we pass axolotl extras to the Dockerfile so vllm is included in shipped images (axolotl-ai-cloud#2599)

Author: winglian

.github/workflows/main.yml

@@ -62,6 +62,7 @@ jobs:
             CUDA=${{ matrix.cuda }}
             PYTORCH_VERSION=${{ matrix.pytorch }}
             AXOLOTL_ARGS=${{ matrix.axolotl_args }}
+            AXOLOTL_EXTRAS=${{ matrix.axolotl_extras}}
           file: ./docker/Dockerfile
           push: ${{ github.event_name != 'pull_request' }}
           tags: |