### 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 ERR_PARSE_ERROR;
	}
	GDScriptAnalyzer analyzer(&parser);
	err = analyzer.analyze();
	if (err) {
		if (EngineDebugger::is_active()) {
			GDScriptLanguage::get_singleton()->debug_break_parse(_get_debug_path(), parser.get_errors().front()->get().line, "Parser Error: " + parser.get_errors().front()->get().message);
		}
		const List<GDScriptParser::ParserError>::Element *e = parser.get_errors().front();
		while (e != nullptr) {
			_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), e->get().line, ("Parse Error: " + e->get().message).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
			e = e->next();
		}
		reloading = false;
		return ERR_PARSE_ERROR;
	}
	can_run = ScriptServer::is_scripting_enabled() || parser.is_tool();
	GDScriptCompiler compiler;
	err = compiler.compile(&parser, this, p_keep_state);
	if (err) {
		if (can_run) {
			if (EngineDebugger::is_active()) {
				GDScriptLanguage::get_singleton()->debug_break_parse(_get_debug_path(), compiler.get_error_line(), "Parser Error: " + compiler.get_error());
			}
			_err_print_error("GDScript::reload", path.is_empty() ? "built-in" : (const char *)path.utf8().get_data(), compiler.get_error_line(), ("Compile Error: " + compiler.get_error()).utf8().get_data(), false, ERR_HANDLER_SCRIPT);
			reloading = false;
			return ERR_COMPILATION_FAILED;
		} else {
			reloading = false;
			return err;