add polyfills or drop 8.2 support

selfnote because sb supports php 8.2 in theory yet uses a php 8.3+ exception class and i didn't even realize this until recently Oops

iirc i only kept 8.2 support because i used to develop on windows using xampp, but it hasnt been updated for 2 years and native windows support on opensb hasnt been supported for over a year. prod currently uses 8.4 while my development instances use 8.5.