Replace str with _StrOrPromise where the latter is expected.

Fixes typeddjango#1231

Signed-off-by: Zixuan James Li <[email protected]>

Author: PIG208

django-stubs/contrib/auth/mixins.pyi

@@ -2,14 +2,15 @@ from typing import Any, Callable, Optional, Sequence
 
 from django import http
 from django.http.response import HttpResponseBase, HttpResponseRedirect
+from django.utils.functional import _StrOrPromise
 
 class AccessMixin:
     login_url: Any = ...
-    permission_denied_message: str = ...
+    permission_denied_message: _StrOrPromise = ...
     raise_exception: bool = ...
     redirect_field_name: Any = ...
     def get_login_url(self) -> str: ...
-    def get_permission_denied_message(self) -> str: ...
+    def get_permission_denied_message(self) -> _StrOrPromise: ...
     def get_redirect_field_name(self) -> str: ...
     def handle_no_permission(self) -> HttpResponseRedirect: ...
 

django-stubs/contrib/messages/views.pyi

@@ -2,8 +2,9 @@ from typing import Dict
 
 from django.forms.forms import BaseForm
 from django.http.response import HttpResponse
+from django.utils.functional import _StrOrPromise
 
 class SuccessMessageMixin:
-    success_message: str = ...
+    success_message: _StrOrPromise = ...
     def form_valid(self, form: BaseForm) -> HttpResponse: ...
-    def get_success_message(self, cleaned_data: Dict[str, str]) -> str: ...
+    def get_success_message(self, cleaned_data: Dict[str, str]) -> _StrOrPromise: ...