### 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)

Vector2 off;
	bool line_clicked = false;
	float text_rect_begin = 0.0;
	int char_pos = -1;
	Line &l = p_frame->lines[p_line];
	MutexLock lock(l.text_buf->get_mutex());
	bool rtl = (l.text_buf->get_direction() == TextServer::DIRECTION_RTL);
	bool lrtl = is_layout_rtl();
	
	bool table_hit = false;
	Vector2i table_range;
	float table_offy = 0.f;
	ItemFrame *table_click_frame = nullptr;
	int table_click_line = -1;
	Item *table_click_item = nullptr;
	int table_click_char = -1;
	for (int line = 0; line < l.text_buf->get_line_count(); line++) {
		RID rid = l.text_buf->get_line_rid(line);
		float width = l.text_buf->get_width();
		float length = TS->shaped_text_get_width(rid);
		if (rtl) {
			off.x = p_width - l.offset.x - width;
			if (!lrtl && p_frame == main) { 
				off.x -= scroll_w;
			}
		} else {
			off.x = l.offset.x;
			if (lrtl && p_frame == main) { 
				off.x += scroll_w;
			}