Rollback rich utils

Author: waketzheng

typer/rich_utils.py

@@ -2,6 +2,7 @@
 
 import inspect
 import io
+import sys
 from collections import defaultdict
 from gettext import gettext as _
 from os import getenv
@@ -22,9 +23,13 @@
 from rich.text import Text
 from rich.theme import Theme
 from rich.traceback import Traceback
-from typer._typing import Literal
 from typer.models import DeveloperExceptionConfig
 
+if sys.version_info >= (3, 9):
+    from typing import Literal
+else:
+    from typing_extensions import Literal
+
 # Default styles
 STYLE_OPTION = "bold cyan"
 STYLE_SWITCH = "bold green"