### Godot version

4.1.dev

### System information

Win11

### Issue description

I load a non-existing GDScript, but it still returns a valid instance instead of null.
```gdscript
@tool
extends EditorScript

func _run():
	var s = ResourceLoader.load("non_exists.gd", "", ResourceLoader.CACHE_MODE_IGNORE)
	print(s)
	assert(s == null)

```

```
  Attempt to open script 'res://non_exists.gd' resulted in error 'File not found'.
<GDScript#-9223369015982753437>
  res://new_script.gd:7 - Assertion failed.

```

### Steps to reproduce

N/A

### Minimal reproduction project

N/A
} else {
				for (List<Pair<StringName, Variant>>::Element *G = saved_state.front(); G; G = G->next()) {
					script_inst->set(G->get().first, G->get().second);
				}
			}
			scr->pending_reload_state.erase(obj->get_instance_id()); 
		}
		
	}
#endif
}
void GDScriptLanguage::frame() {
	calls = 0;
#ifdef DEBUG_ENABLED
	if (profiling) {
		MutexLock lock(this->mutex);
		SelfList<GDScriptFunction> *elem = function_list.first();
		while (elem) {
			elem->self()->profile.last_frame_call_count = elem->self()->profile.frame_call_count;
			elem->self()->profile.last_frame_self_time = elem->self()->profile.frame_self_time;
			elem->self()->profile.last_frame_total_time = elem->self()->profile.frame_total_time;
			elem->self()->profile.frame_call_count = 0;
			elem->self()->profile.frame_self_time = 0;
			elem->self()->profile.frame_total_time = 0;
			elem = elem->next();
		}
	}
#endif
}
void GDScriptLanguage::get_reserved_words(List<String> *p_words) const {