### 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
ERR_FAIL_INDEX_V(p_column, columns.size(), false);
	return columns[p_column].expand;
}
int Tree::get_column_expand_ratio(int p_column) const {
	ERR_FAIL_INDEX_V(p_column, columns.size(), 1);
	return columns[p_column].expand_ratio;
}
bool Tree::is_column_clipping_content(int p_column) const {
	ERR_FAIL_INDEX_V(p_column, columns.size(), false);
	return columns[p_column].clip_content;
}
TreeItem *Tree::get_selected() const {
	return selected_item;
}
void Tree::set_selected(TreeItem *p_item, int p_column) {
	ERR_FAIL_INDEX(p_column, columns.size());
	ERR_FAIL_COND(!p_item);
	select_single_item(p_item, get_root(), p_column);
}
int Tree::get_selected_column() const {
	return selected_col;
}
TreeItem *Tree::get_edited() const {
	return edited_item;
}
int Tree::get_edited_column() const {
	return edited_col;
}
TreeItem *Tree::get_next_selected(TreeItem *p_item) {