### Godot version

4.0 beta 10

### System information

Windows 11 Vulkan

### Issue description

Looked through the issues list, but couldn't find something like this, sorry in advance if this has already been reported.

There is a few cases (in the pictures below) where list of Actions in Input Map may not always show a scrollbar even if the actions list overflows (I imagine this could also happen for the widget that Input Map uses).

![image](https://user-images.githubusercontent.com/39958198/210003566-cf60dbaf-921f-485b-b0a9-51ffc28d0244.png)

![New Bitmap image](https://user-images.githubusercontent.com/39958198/210004079-8eb2e6a1-0cf5-4a7c-8905-a4e3cfd0ec5d.png)

![image](https://user-images.githubusercontent.com/39958198/210004165-a6b6790b-248a-4f68-b4d0-b44b25afdf4f.png)

![image](https://user-images.githubusercontent.com/39958198/210004537-aca52194-a464-48b9-b818-24782706de45.png)


### Steps to reproduce

The pictures are clearer than anything I could write here: "a picture is worth 1000 words"

### Minimal reproduction project

N/A
return parent;
}
TreeItem *TreeItem::get_first_child() const {
	return first_child;
}
TreeItem *TreeItem::_get_prev_visible(bool p_wrap) {
	TreeItem *current = this;
	TreeItem *prev_item = current->get_prev();
	if (!prev_item) {
		current = current->parent;
		if (current == tree->root && tree->hide_root) {
			return nullptr;
		} else if (!current) {
			if (p_wrap) {
				current = this;
				TreeItem *temp = this->get_next_visible();
				while (temp) {
					current = temp;
					temp = temp->get_next_visible();
				}