fixed build error of image name

Author: sandeepgupta12

.github/workflows/ppc64le.yml

@@ -43,6 +43,6 @@ jobs:
     uses: ./.github/workflows/_linux-build.yml
     with:
       build-environment: linux-ppc64le-binary-manywheel
-      docker-image-name: pytorch/manylinuxppc64le-builder
+      docker-image-name: manylinuxppc64le-builder
       runner: ubuntu-24.04-ppc64le
     secrets: inherit