Merge pull request godotengine#111172 from HolonProduction/rm-subclass-count

Remove unused `GDScript::subclass_count`

Author: Repiteo

modules/gdscript/gdscript.h

@@ -174,7 +174,6 @@ class GDScript : public Script {
 	Error _static_init();
 	void _static_default_init(); // Initialize static variables with default values based on their types.
 
-	int subclass_count = 0;
 	RBSet<Object *> instances;
 	bool destructing = false;
 	bool clearing = false;