### 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
int current = 0;
#ifdef DEBUG_ENABLED
	MutexLock lock(this->mutex);
	SelfList<GDScriptFunction> *elem = function_list.first();
	while (elem) {
		if (current >= p_info_max) {
			break;
		}
		if (elem->self()->profile.last_frame_call_count > 0) {
			p_info_arr[current].call_count = elem->self()->profile.last_frame_call_count;
			p_info_arr[current].self_time = elem->self()->profile.last_frame_self_time;
			p_info_arr[current].total_time = elem->self()->profile.last_frame_total_time;
			p_info_arr[current].signature = elem->self()->profile.signature;
			current++;
		}
		elem = elem->next();
	}
#endif
	return current;
}
struct GDScriptDepSort {
	
	bool operator()(const Ref<GDScript> &A, const Ref<GDScript> &B) const {