### 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
if (hide_folding == p_hide) {
		return;
	}
	hide_folding = p_hide;
	queue_redraw();
}
bool Tree::is_folding_hidden() const {
	return hide_folding;
}
void Tree::set_enable_recursive_folding(bool p_enable) {
	enable_recursive_folding = p_enable;
}
bool Tree::is_recursive_folding_enabled() const {
	return enable_recursive_folding;
}
void Tree::set_drop_mode_flags(int p_flags) {
	if (drop_mode_flags == p_flags) {
		return;
	}
	drop_mode_flags = p_flags;
	if (drop_mode_flags == 0) {
		drop_mode_over = nullptr;
	}
	queue_redraw();
}
int Tree::get_drop_mode_flags() const {
	return drop_mode_flags;
}
void Tree::set_edit_checkbox_cell_only_when_checkbox_is_pressed(bool p_enable) {