Improve UnicodeTranslateError stub (#6397)

Author: AlexWaygood

stdlib/builtins.pyi

@@ -1628,7 +1628,14 @@ class UnicodeEncodeError(UnicodeError):
     reason: str
     def __init__(self, __encoding: str, __object: str, __start: int, __end: int, __reason: str) -> None: ...
 
-class UnicodeTranslateError(UnicodeError): ...
+class UnicodeTranslateError(UnicodeError):
+    encoding: None
+    object: str
+    start: int
+    end: int
+    reason: str
+    def __init__(self, __object: str, __start: int, __end: int, __reason: str) -> None: ...
+
 class Warning(Exception): ...
 class UserWarning(Warning): ...
 class DeprecationWarning(Warning): ...