Remove proxima-nova import attempt

I tried importing the new bootstrap package into PCOC and it didn't like being told to import a font from the url (through the package or whatever).

I figure since we have font fallbacks configured, and AZ Bootstrap suggests putting the font in the head of pages that use it anyway (https://digital.arizona.edu/arizona-bootstrap/docs/2.0/content/font/#global-settings) we might as well not mess with trying to package it as part of our styling.

Full Changelog: v2.2.0...v2.2.1