use LiteralString for Sentinel name

DetachHead · web-flow · commit 219ed4f04c60 · 2026-07-27T15:20:13.000+10:00
see python/typeshed#16094
diff --git a/src/typing_extensions.py b/src/typing_extensions.py
@@ -188,7 +188,7 @@ class sentinel:
 
         def __init__(
             self,
-            __name: str = _sentinel_placeholder,
+            __name: LiteralString = _sentinel_placeholder,
             __repr: typing.Optional[str] = _sentinel_placeholder,
             /,
             *,
