Add option --plugin-dirs (#11277)

Closes #3260
Authored by: imranh2, coletdjnz

Co-authored-by: coletdjnz <coletdjnz@protonmail.com>

yt_dlp/utils/_utils.py

@@ -4897,6 +4897,10 @@ class Config:
     filename = None
     __initialized = False
 
+    # Internal only, do not use! Hack to enable --plugin-dirs
+    # TODO(coletdjnz): remove when plugin globals system is implemented
+    _plugin_dirs = None
+
     def __init__(self, parser, label=None):
         self.parser, self.label = parser, label
         self._loaded_paths, self.configs = set(), []