pre-commit: fix pygrep hooks

Fixes https://github.com/NixOS/nixpkgs/issues/173707

pkgs/tools/misc/pre-commit/default.nix

@@ -32,6 +32,7 @@ buildPythonApplication rec {
   patches = [
     ./languages-use-the-hardcoded-path-to-python-binaries.patch
     ./hook-tmpl.patch
+    ./pygrep-pythonpath.patch
   ];
 
   propagatedBuildInputs = [

pkgs/tools/misc/pre-commit/pygrep-pythonpath.patch

@@ -0,0 +1,13 @@
+diff --git a/pre_commit/languages/pygrep.py b/pre_commit/languages/pygrep.py
+index ec55560..44e08a1 100644
+--- a/pre_commit/languages/pygrep.py
++++ b/pre_commit/languages/pygrep.py
+@@ -98,7 +98,7 @@ def run_hook(
+         color: bool,
+ ) -> tuple[int, bytes]:
+     cmd = (sys.executable, '-m', __name__, *args, entry)
+-    return xargs(cmd, file_args, color=color)
++    return xargs(cmd, file_args, color=color, env={ "PYTHONPATH": ':'.join(sys.path) })
+ 
+ 
+ def main(argv: Sequence[str] | None = None) -> int: