fix: resolve ruff RUF033 and test assertion after msgspec removal

- Remove default value from CustomToken.__post_init__ leeway param
  (defaults should be on InitVar field, not __post_init__ parameter)
- Pass random_field as int since msgspec type coercion is no longer used

Author: Krishnachaitanyakc

tests/unit/test_security/test_jwt/test_auth.py

@@ -191,8 +191,7 @@ def handler(request: Request[Any, CustomToken, Any]) -> dict[str, Any]:
         jwt_auth.create_token(
             "foo",
             token_extras={"foo": "bar"},
-            # pass a string here as value to ensure things get converted properly
-            random_field="2",
+            random_field=2,
         ),
     )
 
@@ -851,7 +850,7 @@ async def test_jwt_auth_verify_exp(
 ) -> None:
     @dataclasses.dataclass
     class CustomToken(Token):
-        def __post_init__(self, leeway: float = 0) -> None:
+        def __post_init__(self, leeway: float) -> None:
             pass
 
     jwt_auth, client = create_jwt_app(verify_expiry=verify_expiry, token_cls=CustomToken)