Always use parens around division in our .less files.

Review Request #12404 — Created June 23, 2022 and submitted — Latest diff uploaded

Review Board

LessCSS 4.0 began to require parenthesis around division by default, in
order to force immediate evaluation. This change was made because CSS
now uses / as non-math syntax for a lot of modern rules. LessCSS
previously allowed codebases to opt into a parens-division mode that
played nicer with modern CSS, but with 4.0 they made that mode the

We were already using parens around most of our division, but there were
a couple cases that produced outright errors, and some that likely were
now outputting bad CSS.

This change adds parens around all division remaining in our codebase.

Successfully compiled the CSS.

Went through the UI. Didn't see any obvious breakages, but we'll need
to test more as we move this to production.