Fix IndexFile forwardref

Author: Yobmod

git/objects/submodule/base.py

@@ -7,8 +7,6 @@
 from unittest import SkipTest
 import uuid
 
-from git import IndexFile
-
 import git
 from git.cmd import Git
 from git.compat import (
@@ -58,6 +56,7 @@
 
 if TYPE_CHECKING:
     from git.repo import Repo
+    from git.index import IndexFile
 
 
 # -----------------------------------------------------------------------------
@@ -1012,7 +1011,7 @@ def set_parent_commit(self, commit: Union[Commit_ish, None], check: bool = True)
         return self
 
     @unbare_repo
-    def config_writer(self, index: Union[IndexFile, None] = None, write: bool = True) -> SectionConstraint:
+    def config_writer(self, index: Union['IndexFile', None] = None, write: bool = True) -> SectionConstraint:
         """:return: a config writer instance allowing you to read and write the data
             belonging to this submodule into the .gitmodules file.
 

git/types.py

@@ -36,8 +36,6 @@
 
 Lit_config_levels = Literal['system', 'global', 'user', 'repository']
 
-T = TypeVar('T', bound=Literal['system', 'global', 'user', 'repository'], covariant=True)
-
 
 class ConfigLevels_NT(NamedTuple):
     """NamedTuple of allowed CONFIG_LEVELS"""