Update flake8 additional dependencies, fix warning

This bumps the versions of the flake8 plugins specified with pinned
versions as additional dependencies of flake8 for pre-commit.

Doing so gains a warning about a call to warnings.warn with no
stacklevel argument. This appears to be the uncommon case where the
implifit effect of stacklevel=1 is intended, so I have made that
explicit, which clarifies this intent and dismisses the warning.

Author: EliahKagan

Diff for: .pre-commit-config.yaml

@@ -5,8 +5,8 @@ repos:
       - id: flake8
         additional_dependencies:
           [
-            flake8-bugbear==22.12.6,
-            flake8-comprehensions==3.10.1,
+            flake8-bugbear==23.9.16,
+            flake8-comprehensions==3.14.0,
             flake8-typing-imports==1.14.0,
           ]
         exclude: ^doc|^git/ext/|^test/

Diff for: git/repo/base.py

@@ -206,7 +206,8 @@ def __init__(
         if expand_vars and re.search(self.re_envvars, epath):
             warnings.warn(
                 "The use of environment variables in paths is deprecated"
-                + "\nfor security reasons and may be removed in the future!!"
+                + "\nfor security reasons and may be removed in the future!!",
+                stacklevel=1,
             )
         epath = expand_path(epath, expand_vars)
         if epath is not None: