typing alias (#399)

openai hit funny edge case
https://statsigconnect.slack.com/archives/C04QTFAJCS3/p1738002461980959?thread_ts=1735850796.978909&cid=C04QTFAJCS3

Author: kat-statsig

statsig/statsig_user.py

@@ -1,12 +1,14 @@
 from dataclasses import dataclass
-from typing import Optional, Union, Sequence, Mapping, Dict
+from typing import Optional, Union, Sequence, Mapping, Dict # pylint: disable=unused-import
+
+from typing_extensions import TypeAliasType
 
 from .statsig_environment_tier import StatsigEnvironmentTier
 from .statsig_errors import StatsigValueError
 from .utils import str_or_none, to_raw_dict_or_none, djb2_hash_for_dict
 
 JSONPrimitive = Union[str, int, float, bool, None]
-JSONValue = Union[JSONPrimitive, Sequence["JSONValue"], Mapping[str, "JSONValue"]]
+JSONValue = TypeAliasType("JSONValue", 'Union[JSONPrimitive, Sequence["JSONValue"], Mapping[str, "JSONValue"]]')
 
 
 @dataclass