drop collision check for custom mods

Mod hashes are taken from the directory names, which cannot be the same
at the filesystem level. Custom mod hashes are also unique from local
mods because they are given a different namespace.

dzgui/controllers/emitter.py

@@ -156,7 +156,7 @@ class Emitter(GObject.GObject):
         pass
 
     @GObject.Signal(flags=GObject.SignalFlags.RUN_LAST, arg_types=(object, str, bool))
-    def custom_mods_loaded(self, store: "FastInsertListStore", folder: str, has_duplicates: bool) -> None:
+    def custom_mods_loaded(self, store: "FastInsertListStore", folder: str) -> None:
         pass
 
     @GObject.Signal(flags=GObject.SignalFlags.RUN_LAST, arg_types=(str, bool))