On Ubuntu 24.04, PHP 8.2 is not in the default apt repos.
The ondrej/php PPA must be added before package installation.
Previously this was a separate step that could be bypassed when
running a locally-cached (pre-fix) copy of install.sh.
Changes:
- Add self-update block: script fetches latest version from GitHub
and re-execs itself, so stale local copies are never used
- Remove standalone php_ppa step; PPA is now added unconditionally
inside the packages step (checks if already present to avoid
duplicate adds on re-runs)
- Idempotent: grep checks sources.list before calling
add-apt-repository
NixReaper