9 guides php fpm (#2955)

* Add admonition about `rkhunter` being dead
* admonition added for version 9

* Edit `guides/web/php.md`for 9:
* Strip out 8 content options
* update PHP versions of Appstream
* remove Remi repository options
* update content of PHP check version
* replace most "we" references with "you"
* update passive voice phrases to active voice
* some sentence simplification
* ensure processes and packages are in back ticks

Author: sspencerwire