### 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)

ERR_FAIL_COND(p_event.is_null());
	Ref<InputEventMouseButton> b = p_event;
	if (b.is_valid()) {
		if (b->get_button_index() == MouseButton::LEFT) {
			if (b->is_pressed() && !b->is_double_click()) {
				scroll_updated = false;
				ItemFrame *c_frame = nullptr;
				int c_line = 0;
				Item *c_item = nullptr;
				int c_index = 0;
				bool outside;
				selection.drag_attempt = false;
				_find_click(main, b->get_position(), &c_frame, &c_line, &c_item, &c_index, &outside, false);
				if (c_item != nullptr) {
					if (selection.enabled) {
						selection.click_frame = c_frame;
						selection.click_item = c_item;
						selection.click_line = c_line;
						selection.click_char = c_index;
						
						if (selection.active) {
							if (drag_and_drop_selection_enabled && _is_click_inside_selection()) {
								selection.drag_attempt = true;
								selection.click_item = nullptr;
							} else {
								selection.from_frame = nullptr;
								selection.from_line = 0;