Drop include_hidden=all_files from iglob instead

as per review users can still do `/learn .*` and
it would be in line how `bash`/`zsh` works (e.g.
`ls * -a` does not files in hidden directories
but `ls .*` does).

packages/jupyter-ai/jupyter_ai/document_loaders/directory.py

@@ -4,7 +4,6 @@
 import tarfile
 from datetime import datetime
 from glob import iglob
-from inspect import signature
 from pathlib import Path
 from typing import List
 
@@ -137,12 +136,7 @@ def collect_filepaths(path, all_files: bool):
         filepaths = walk_directory(path, all_files)
     else:
         filepaths = []
-        glob_iterator = (
-            iglob(str(path), recursive=True, include_hidden=all_files)
-            if "include_hidden" in signature(iglob).parameters
-            else iglob(str(path), recursive=True)
-        )
-        for glob_path in glob_iterator:
+        for glob_path in iglob(str(path), recursive=True):
             if os.path.isfile(glob_path):
                 filepaths.append(Path(glob_path))
     valid_exts = {j.lower() for j in SUPPORTED_EXTS}