typing: Import StrPromise alias from django_stubs_ext.

This saves us from using a conditional import.

Signed-off-by: Zixuan James Li <p359101898@gmail.com>

zerver/lib/types.py

@@ -1,23 +1,10 @@
 import datetime
 from dataclasses import dataclass
-from typing import (
-    TYPE_CHECKING,
-    Any,
-    Callable,
-    Dict,
-    List,
-    Optional,
-    Tuple,
-    TypedDict,
-    TypeVar,
-    Union,
-)
+from typing import Any, Callable, Dict, List, Optional, Tuple, TypedDict, TypeVar, Union
 
+from django_stubs_ext import StrPromise
 from typing_extensions import NotRequired
 
-if TYPE_CHECKING:
-    from django.utils.functional import _StrPromise as StrPromise
-
 # See zerver/lib/validator.py for more details of Validators,
 # including many examples
 ResultT = TypeVar("ResultT")
@@ -51,11 +38,9 @@ class ProfileDataElementUpdateDict(TypedDict):
 
 ProfileData = List[ProfileDataElement]
 
-FieldElement = Tuple[
-    int, "StrPromise", Validator[ProfileDataElementValue], Callable[[Any], Any], str
-]
-ExtendedFieldElement = Tuple[int, "StrPromise", ExtendedValidator, Callable[[Any], Any], str]
-UserFieldElement = Tuple[int, "StrPromise", RealmUserValidator, Callable[[Any], Any], str]
+FieldElement = Tuple[int, StrPromise, Validator[ProfileDataElementValue], Callable[[Any], Any], str]
+ExtendedFieldElement = Tuple[int, StrPromise, ExtendedValidator, Callable[[Any], Any], str]
+UserFieldElement = Tuple[int, StrPromise, RealmUserValidator, Callable[[Any], Any], str]
 
 ProfileFieldData = Dict[str, Union[Dict[str, str], str]]