Removing Inventory Items with Children Items breaks Inventory count

[corbosman]

NetBox version

v3.6.3

Python version

3.8

Steps to Reproduce

1. add an inventory item to a device
2. add a child inventory item to the item from 1.
3. remove both at the same time

Expected Behavior

For the inventory item count to be correct

Observed Behavior

Inventory count is -1