fix: satisfy pyright for redirect URI normalization

Author: 冯基魁

src/mcp/shared/auth.py

@@ -1,4 +1,4 @@
-from typing import Any, Literal
+from typing import Any, Literal, cast
 
 from pydantic import AnyHttpUrl, AnyUrl, BaseModel, ConfigDict, Field, field_validator
 
@@ -88,7 +88,8 @@ class OAuthClientMetadata(BaseModel):
     @classmethod
     def _coerce_redirect_uris_to_any_url(cls, v: object) -> object:
         if isinstance(v, list):
-            return [str(item) if isinstance(item, AnyUrl) else item for item in v]
+            redirect_uris = cast(list[object], v)
+            return [str(item) if isinstance(item, AnyUrl) else item for item in redirect_uris]
         return v
 
     @field_validator(