### 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)

switch (p_option) {
		case MENU_COPY: {
			selection_copy();
		} break;
		case MENU_SELECT_ALL: {
			select_all();
		} break;
	}
}
void RichTextLabel::_draw_fbg_boxes(RID p_ci, RID p_rid, Vector2 line_off, Item *it_from, Item *it_to, int start, int end, int fbg_flag) {