simplify resources_path logic to reolve type hint

The following logic was leading to type hint issues:

>	inspect.getfile(inspect.currentframe())

But this code is overly complex for what it does is the same as
simply __file__. So we kill two birds with one stone, so to speak.

dangerzone/global_common.py

@@ -1,8 +1,6 @@
 import gzip
-import inspect
 import json
 import logging
-import os
 import pathlib
 import platform
 import shutil