### 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
return rpc_config;
}
void GDScript::unload_static() const {
	GDScriptCache::remove_script(fully_qualified_name);
}
Variant GDScript::callp(const StringName &p_method, const Variant **p_args, int p_argcount, Callable::CallError &r_error) {
	GDScript *top = this;
	while (top) {
		HashMap<StringName, GDScriptFunction *>::Iterator E = top->member_functions.find(p_method);
		if (E) {
			ERR_FAIL_COND_V_MSG(!E->value->is_static(), Variant(), "Can't call non-static function '" + String(p_method) + "' in script.");
			return E->value->call(nullptr, p_args, p_argcount, r_error);
		}
		top = top->_base;
	}
	
	return Script::callp(p_method, p_args, p_argcount, r_error);
}
bool GDScript::_get(const StringName &p_name, Variant &r_ret) const {
	{
		const GDScript *top = this;
		while (top) {
			{
				HashMap<StringName, Variant>::ConstIterator E = top->constants.find(p_name);
				if (E) {
					r_ret = E->value;
					return true;
				}