### Godot version

4.2.dev1

### System information

Manjaro Linux (DE: Cinnamon v5.8.4) 64 bits

### Issue description

The title already explains it. Take a look at the steps to reproduce below.

### Steps to reproduce

In a GDScript `_ready()` function write this:
```print_rich("[color=red]Red line\n2nd red line[/color]")```

the second line is not red and the output is as follow:
![Capture d’écran du 2023-07-29 05-50-16](https://github.com/godotengine/godot/assets/102065761/554038c6-d128-40c9-8c88-237b44b35b12)

I tested all the the possible BBCodes for the print_rich() method (as stated in the documentation), and of course they all failed.

The RichTextLabel in my projects works as expected.

### Minimal reproduction project

N/A
EditorLog *self = static_cast<EditorLog *>(p_self);
	String err_str;
	if (p_errorexp && p_errorexp[0]) {
		err_str = String::utf8(p_errorexp);
	} else {
		err_str = String::utf8(p_file) + ":" + itos(p_line) + " - " + String::utf8(p_error);
	}
	if (p_editor_notify) {
		err_str += " (User)";
	}
	MessageType message_type = p_type == ERR_HANDLER_WARNING ? MSG_TYPE_WARNING : MSG_TYPE_ERROR;
	if (self->current != Thread::get_caller_id()) {
		callable_mp(self, &EditorLog::add_message).bind(err_str, message_type).call_deferred();
	} else {
		self->add_message(err_str, message_type);
	}
}
void EditorLog::_update_theme() {