Keep root lint scoped to GitPython

The imported gitdb and smmap histories contain their own legacy formatting
and configuration. Letting GitPython's root pre-commit configuration scan
those trees produced unrelated failures and would turn the subtree merge into
a wholesale reformat.

Exclude the imported project directories at the root so existing GitPython
checks retain their previous scope; each dependency continues to own its
source style.

Author: codex

.pre-commit-config.yaml

@@ -1,3 +1,5 @@
+exclude: ^(?:gitdb|smmap)/
+
 repos:
 - repo: https://github.com/codespell-project/codespell
   rev: v2.4.2

test/test_submodule.py

@@ -508,8 +508,6 @@ def test_root_module(self, rwrepo):
         with rm.config_writer():
             pass
 
-        rsmsp = ["git/ext/gitdb", "gitdb/ext/smmap"]
-
         # Cannot set the parent commit as root module's path didn't exist.
         self.assertRaises(ValueError, rm.set_parent_commit, "HEAD")