[ytdl] support specifying filesystem paths as 'module' (#6991)

gallery_dl/util.py

@@ -770,7 +770,7 @@ def import_file(path):
         finally:
             del sys.path[0]
     else:
-        return __import__(name)
+        return __import__(name.replace("-", "_"))
 
 
 def build_duration_func(duration, min=0.0):

gallery_dl/ytdl.py

@@ -20,7 +20,7 @@ def import_module(module_name):
             return __import__("yt_dlp")
         except (ImportError, SyntaxError):
             return __import__("youtube_dl")
-    return __import__(module_name.replace("-", "_"))
+    return util.import_file(module_name)
 
 
 def construct_YoutubeDL(module, obj, user_opts, system_opts=None):