### 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
_get_script_property_list(r_list, true);
}
bool GDScript::has_method(const StringName &p_method) const {
	return member_functions.has(p_method);
}
MethodInfo GDScript::get_method_info(const StringName &p_method) const {
	HashMap<StringName, GDScriptFunction *>::ConstIterator E = member_functions.find(p_method);
	if (!E) {
		return MethodInfo();
	}
	GDScriptFunction *func = E->value;
	MethodInfo mi;
	mi.name = E->key;
	for (int i = 0; i < func->get_argument_count(); i++) {
		mi.arguments.push_back(func->get_argument_type(i));
	}
	mi.return_val = func->get_return_type();
	return mi;
}
bool GDScript::get_property_default_value(const StringName &p_property, Variant &r_value) const {