### 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
if (clear_data == nullptr) {
		clear_data = &data;
		is_root = true;
	}
	RBSet<GDScript *> must_clear_dependencies = get_must_clear_dependencies();
	for (GDScript *E : must_clear_dependencies) {
		clear_data->scripts.insert(E);
		E->clear(clear_data);
	}
	for (const KeyValue<StringName, GDScriptFunction *> &E : member_functions) {
		clear_data->functions.insert(E.value);
	}
	member_functions.clear();
	for (KeyValue<StringName, GDScript::MemberInfo> &E : member_indices) {
		clear_data->scripts.insert(E.value.data_type.script_type_ref);
		E.value.data_type.script_type_ref = Ref<Script>();
	}
	for (KeyValue<StringName, GDScript::MemberInfo> &E : static_variables_indices) {
		clear_data->scripts.insert(E.value.data_type.script_type_ref);
		E.value.data_type.script_type_ref = Ref<Script>();
	}
	static_variables.clear();
	static_variables_indices.clear();
	if (implicit_initializer) {
		clear_data->functions.insert(implicit_initializer);
		implicit_initializer = nullptr;
	}
	if (implicit_ready) {