### Godot version

4.x

### System information

Windows 10

### Issue description

The `Search Result` panel is not correctly updated when changing the theme.

https://user-images.githubusercontent.com/66004280/208964493-d0423b78-3418-44c9-95ed-822fd34c4720.mp4



### Steps to reproduce

1. Search something
2. Change the theme

### Minimal reproduction project

--
_searching = false;
	_current_dir = "";
	set_process(false);
}
void FindInFiles::_process() {
	
	OS &os = *OS::get_singleton();
	uint64_t time_before = os.get_ticks_msec();
	while (is_processing()) {
		_iterate();
		uint64_t elapsed = (os.get_ticks_msec() - time_before);
		if (elapsed > 8) { 
			break;
		}
	}
}
void FindInFiles::_iterate() {
	if (_folders_stack.size() != 0) {
		
		PackedStringArray &folders_to_scan = _folders_stack.write[_folders_stack.size() - 1];
		if (folders_to_scan.size() != 0) {