sync: ensure RepoChangedException propagated

Prior to this change RepoChangedException would be caught and re-rasied
as a different exception. This would prevent RepoChangedException
handler from running in main.py

Bug: b/323232806
Change-Id: I9055ff95d439d6ff225206c5bf1755cc718bcfcc
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/407144
Tested-by: Josip Sokcevic <sokcevic@google.com>
Reviewed-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

subcmds/sync.py

diff --git a/subcmds/sync.py b/subcmds/sync.py
index 233c9f4..6004e30 100644
--- a/subcmds/sync.py
+++ b/subcmds/sync.py
@@ -1628,7 +1628,7 @@
         errors = []
         try:
             self._ExecuteHelper(opt, args, errors)
-        except RepoExitError:
+        except (RepoExitError, RepoChangedException):
             raise
         except (KeyboardInterrupt, Exception) as e:
             raise RepoUnhandledExceptionError(e, aggregate_errors=errors)