### Godot version

4.2 f5696c3

### System information

Windows 10 x64

### Issue description

![image](https://github.com/godotengine/godot/assets/2223172/7ad0e3b6-9599-4f7b-a07c-da54779e647a)


### Steps to reproduce

1. Add node
2. Attach a built-in script
3. Add child node
4. Add script to the child node
5. In some method write `get_parent().bui`

### Minimal reproduction project

N/A
ScriptLanguage::CodeCompletionOption set("set", ScriptLanguage::CODE_COMPLETION_KIND_PLAIN_TEXT);
			options.insert(set.display, set);
			r_forced = true;
		} break;
		case GDScriptParser::COMPLETION_PROPERTY_METHOD: {
			if (!completion_context.current_class) {
				break;
			}
			for (int i = 0; i < completion_context.current_class->members.size(); i++) {
				const GDScriptParser::ClassNode::Member &member = completion_context.current_class->members[i];
				if (member.type != GDScriptParser::ClassNode::Member::FUNCTION) {
					continue;
				}
				if (member.function->is_static) {
					continue;
				}
				ScriptLanguage::CodeCompletionOption option(member.function->identifier->name, ScriptLanguage::CODE_COMPLETION_KIND_FUNCTION);
				options.insert(option.display, option);
			}
			r_forced = true;
		} break;
		case GDScriptParser::COMPLETION_ASSIGN: {
			GDScriptCompletionIdentifier type;
			if (!completion_context.node || completion_context.node->type != GDScriptParser::Node::ASSIGNMENT) {
				break;
			}
			if (!_guess_expression_type(completion_context, static_cast<const GDScriptParser::AssignmentNode *>(completion_context.node)->assignee, type)) {
				_find_identifiers(completion_context, false, options, 0);
				r_forced = true;
				break;