cmd/git(docs[GitTagManager.run]): use ellipsis instead of 'in' check

why: Cleaner doctest using built-in ELLIPSIS matching
what:
- Replace 'tag' in mgr.run() pattern with '...tag...' ellipsis

Author: tony

src/libvcs/cmd/git.py

@@ -6068,8 +6068,8 @@ def run(
         >>> mgr = GitTagManager(path=example_git_repo.path)
         >>> mgr.create(name='run-doctest-tag', message='For doctest')
         ''
-        >>> 'run-doctest-tag' in mgr.run()
-        True
+        >>> mgr.run()
+        '...run-doctest-tag...'
         """
         local_flags = local_flags if isinstance(local_flags, list) else []
         if command is not None: