Local source may not work when there are non image files in the path

[ksh-b]

Traceback (most recent call last):
  File "/home/kshib/.local/bin/wanda", line 8, in <module>
    sys.exit(run())
             ^^^^^
  File "/home/kshib/.local/pipx/venvs/wanda/lib/python3.12/site-packages/wanda/wanda.py", line 148, in run
    wp = local(term)
         ^^^^^^^^^^^
  File "/home/kshib/.local/pipx/venvs/wanda/lib/python3.12/site-packages/wanda/sources/extractor.py", line 227, in local
    list(
  File "/home/kshib/.local/pipx/venvs/wanda/lib/python3.12/site-packages/wanda/sources/extractor.py", line 230, in <lambda>
    and filetype.guess(path + f).MIME.startswith("image"),
        ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'MIME'