### Godot version

v4.1.stable.official [970459615]

### System information

Godot v4.1.stable - Windows 10.0.22621 - Vulkan (Forward+) - dedicated NVIDIA GeForce MX330 (NVIDIA; 30.0.15.1169) - 11th Gen Intel(R) Core(TM) i5-1135G7 @ 2.40GHz (8 Threads)

### Issue description

Calling `RichTextLabel`'s `select_all` method has no visual indicator, but it must have one. 

### Steps to reproduce

- Add `RichTextLabel` node
- Set `selection_enabled` value to be `true`
- Call `$RichTextLabel.select_all() `method in `_ready`

### Minimal reproduction project

[RichTextLabel_bug.zip](https://github.com/godotengine/godot/files/12098913/RichTextLabel_bug.zip)

queue_redraw();
		return true;
	}
}
void RichTextLabel::_process_line_caches() {
	
	if (!is_inside_tree()) {
		return;
	}
	MutexLock data_lock(data_mutex);
	Rect2 text_rect = _get_text_rect();
	float ctrl_height = get_size().height;
	int fi = main->first_invalid_line.load();
	int total_chars = main->lines[fi].char_offset;
	float old_scroll = vscroll->get_value();
	float total_height = 0;
	if (fi != 0) {
		int sr = MIN(main->first_invalid_font_line.load(), main->first_resized_line.load());
		
		for (int i = main->first_invalid_font_line.load(); i < fi; i++) {
			_update_line_font(main, i, theme_cache.normal_font, theme_cache.normal_font_size);
			main->first_invalid_font_line.store(i);
			if (stop_thread.load()) {
				return;
			}
		}
		
		if (sr != 0) {
			total_height = _calculate_line_vertical_offset(main->lines[sr - 1]);
		}