Fix for builder repo not pinned in release branch (#72719)
Summary:
Fixes https://github.com/pytorch/pytorch/issues/72655
Please note: Readme.md file change will be done after this change is performed and release specific change is done, so that I will reference the commit of the release specific change in the readme as an example
Pull Request resolved: https://github.com/pytorch/pytorch/pull/72719
Reviewed By: seemethere
Differential Revision: D34177045
Pulled By: atalman
fbshipit-source-id: 2abb7af8cf1337704933c19c0d06022034ec77b4
(cherry picked from commit 31ff276d5e2cacc0e0592d624f3d486d5e8cfd1c)
