Previously the code failed when the repository was in detached HEAD
state (e.g. on CI).

Closes #22405.

PiperOrigin-RevId: 634564660
Change-Id: I60d87f1f24a1dceec6b74709a571c9630cf6bcc5

Commit
https://github.com/bazelbuild/bazel/commit/2028c473ae5d9f7bd053383a1622bb9678d7ab33



Co-authored-by: Florian Weikert <fwe@google.com>