Update moment.js library to 2.29.3

There is a problem with the moment.js library's SRI hash for 2.29.2 on
cdnjs.com 1, which is preventing it to load when $g_cdn_enabled = ON.

The issue has not yet been solved, but moment.js 2.29.3 has been
released and the new version's CDN resources are valid, so we'll upgrade
to that instead of waiting for cdnjs to fix 2.29.2.

Fixes 0029857