### Godot version

4.2 Stable

### System information

Linux

### Issue description

Calling TreeItem set_text() on a TreeItem that was removed via remove_child() causes debugging to end and the application to close without any error message.

### Steps to reproduce

Run the included example to get the debugger to crash. Comment out "treeItem.remove_child(subTreeItem)" for normal behaviour. 

### Minimal reproduction project

[treeItemCrash.zip](https://github.com/godotengine/godot/files/13534005/treeItemCrash.zip)

if (hide_root && !root->get_next_visible()) {
			return;
		}
		if (k->get_unicode() > 0) {
			_do_incr_search(String::chr(k->get_unicode()));
			accept_event();
			return;
		} else {
			if (k->get_keycode() != Key::SHIFT) {
				last_keypress = 0;
			}
		}
	}
	Ref<InputEventMouseMotion> mm = p_event;
	if (mm.is_valid()) {
		Ref<StyleBox> bg = theme_cache.panel_style;
		bool rtl = is_layout_rtl();
		Point2 pos = mm->get_position();
		if (rtl) {
			pos.x = get_size().width - pos.x;
		}
		pos -= theme_cache.panel_style->get_offset();
		Cache::ClickType old_hover = cache.hover_type;
		int old_index = cache.hover_index;
		cache.hover_type = Cache::CLICK_NONE;
		cache.hover_index = 0;
		if (show_column_titles) {
			pos.y -= _get_title_button_height();
			if (pos.y < 0) {
				pos.x += theme_cache.offset.x;