superproject: Remove notice about beta

It's been the default for Android for over a year now, and it's no
longer useful notice.

Change-Id: I53c6f1e7cee8c1b2f408e67d3a6732db3b272bee
Reviewed-on: https://gerrit-review.googlesource.com/c/git-repo/+/438521
Reviewed-by: Gavin Mak <gavinmak@google.com>
Tested-by: Josip Sokcevic <sokcevic@google.com>
Commit-Queue: Josip Sokcevic <sokcevic@google.com>

Author: sokcevicG

git_superproject.py

@@ -307,8 +307,6 @@ def Sync(self, git_event_log):
             )
             return SyncResult(False, False)
 
-        _PrintBetaNotice()
-
         should_exit = True
         if not self._remote_url:
             self._LogWarning(
@@ -452,16 +450,6 @@ def UpdateProjectsRevisionId(self, projects, git_event_log):
         return UpdateProjectsResult(manifest_path, False)
 
 
-@functools.lru_cache(maxsize=10)
-def _PrintBetaNotice():
-    """Print the notice of beta status."""
-    print(
-        "NOTICE: --use-superproject is in beta; report any issues to the "
-        "address described in `repo version`",
-        file=sys.stderr,
-    )
-
-
 @functools.lru_cache(maxsize=None)
 def _UseSuperprojectFromConfiguration():
     """Returns the user choice of whether to use superproject."""