[Django Upgrade] [ENG-3947] Storage region slice subquery issue

[Johnetordoff]

Purpose

Change to cachedprotery in 2.2 broke this https://docs.djangoproject.com/en/4.0/releases/2.2/#cached-property-aliases

This issue was actually created by not retrieving the exact value from a sub-queryset and instead using a subquery as a value.

Changes

QA Notes

Documentation

Side Effects

Ticket