dockerfile name in yml

Author: sandeepgupta12

.github/workflows/ppc64le.yml

@@ -37,7 +37,7 @@ jobs:
           docker run --rm \
             -v pytorch_workspace:/workspace/pytorch \
             -v "${{ github.workspace }}:/repo" \
-            ubuntu bash -c "cp -r /repo/* /workspace/pytorch/"
+            pytorch-ppc64le:ubi9.3 bash -c "cp -r /repo/* /workspace/pytorch/"
 
       - name: Run Docker container and execute build script
         run: |