(torchx/CI) update docker repo to ghcr.io/meta-pytorch/torchx

Differential Revision: D83688082

Pull Request resolved: meta-pytorch#1136

Author: kiukchung

.github/workflows/container.yaml

@@ -32,8 +32,8 @@ jobs:
         run: |
           set -eux
           torchx/runtime/container/build.sh
-          docker tag torchx "ghcr.io/pytorch/torchx:$VERSION"
+          docker tag torchx "ghcr.io/meta-pytorch/torchx:$VERSION"
       - name: Push containers
         run: |
           set -eux
-          docker push "ghcr.io/pytorch/torchx:$VERSION"
+          docker push "ghcr.io/meta-pytorch/torchx:$VERSION"