### 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 if (subclass->extends.size() == 1) {
					*r_base_type = subclass->extends[0]->name;
					subclass = nullptr;
				} else {
					break;
				}
			} else {
				*r_base_type = "RefCounted";
				subclass = nullptr;
			}
		}
	}
	return c->identifier != nullptr ? String(c->identifier->name) : String();
}
GDScriptLanguage::GDScriptLanguage() {
	calls = 0;
	ERR_FAIL_COND(singleton);
	singleton = this;
	strings._init = StaticCString::create("_init");
	strings._static_init = StaticCString::create("_static_init");
	strings._notification = StaticCString::create("_notification");
	strings._set = StaticCString::create("_set");
	strings._get = StaticCString::create("_get");
	strings._get_property_list = StaticCString::create("_get_property_list");
	strings._property_can_revert = StaticCString::create("_property_can_revert");
	strings._property_get_revert = StaticCString::create("_property_get_revert");
	strings._script_source = StaticCString::create("script/source");
	_debug_parse_err_line = -1;
	_debug_parse_err_file = "";