[V3] Actually add compatibility with 3.5.1 (#1155)

* Fix 3.5.1 issue with TYPE_CHECKING

* I hate you

* Smarter...

redbot/core/data_manager.py

@@ -1,6 +1,6 @@
 import sys
 from pathlib import Path
-from typing import TYPE_CHECKING, List
+from typing import List
 import hashlib
 import shutil
 import logging
@@ -8,6 +8,7 @@ import logging
 import appdirs
 
 from .json_io import JsonIO
+from .utils import TYPE_CHECKING
 
 if TYPE_CHECKING:
     from . import Config