Installer needs to be smarter

[HitScan]

Currently there is a single installer for all Debian systems. This will cause problems as installations on Buster require Ondrej Sury's custom php repo in order to run more modern PHP, but Bookworm uses PHP 8.2 by default and requires editing the installer before running it. It wouldn't be particularly difficult to keep track of these few changes (and discard them, when Buster ages out) without user intervention.