Better type for force_text using overloads/Literal

- If a str is passed in, it returns a str.
- If strings_only = True and a "protected type" is passed in, returns that type.
- Default if it doesn't match the overloads: return a str

django-stubs/utils/encoding.pyi

@@ -1,4 +1,6 @@
-from typing import Any, Optional
+from typing import Any, Optional, TypeVar, Union, Literal, overload
+from decimal import Decimal
+import datetime
 
 class DjangoUnicodeDecodeError(UnicodeDecodeError):
     obj: bytes = ...
@@ -8,7 +10,18 @@ python_2_unicode_compatible: Any
 
 def smart_text(s: Any, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> str: ...
 def is_protected_type(obj: Any) -> bool: ...
-def force_text(s: Any, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> Optional[str]: ...
+
+_ProtectedType = TypeVar(
+    "_ProtectedType", Union[None, int, float, Decimal, datetime.datetime, datetime.date, datetime.time]
+)
+@overload
+def force_text(s: str, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> str: ...
+@overload
+def force_text(
+    s: _ProtectedType, encoding: str = ..., strings_only: Literal[True] = ..., errors: str = ...,
+) -> _ProtectedType: ...
+@overload
+def force_text(s: Any, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> str: ...
 def smart_bytes(s: Any, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> bytes: ...
 def force_bytes(s: Any, encoding: str = ..., strings_only: bool = ..., errors: str = ...) -> bytes: ...