Remove PHPUnit from PHP images

[joshtrichards]

v9.4 (currently what we use)

• EoL occurred on February 2, 2024
• Designed for PHP 7.3

https://phpunit.de/supported-versions.html

Docs:

• https://phpunit.de/announcements/phpunit-9.html
• https://phpunit.de/announcements/phpunit-10.html
• https://phpunit.de/announcements/phpunit-11.html
• https://github.com/sebastianbergmann/phpunit/blob/9.6/DEPRECATIONS.md
• https://github.com/sebastianbergmann/phpunit/blob/10.5/DEPRECATIONS.md
• https://github.com/sebastianbergmann/phpunit/blob/11.3/DEPRECATIONS.md

Things to start watching out for now:

• deprecation warnings generated by our current version

TODO:

• Any key benefits other than bug fixes/PHP 8.x specific support?
• Build images with 9.6 to do some preliminary tests against
• Build images with 10 to do some preliminary tests against
• Decide when/if 9.6 is feasible
  • How much will work will it take?
  • Is it even worth it?
• Decide when/if 10.x is feasible
  • How much will work will it take?
  • Is it even worth it?
• Decide when/if 11.x is feasible (can we skip 10.x or will that take too much work for now?) [>= PHP 8.2]
  • How much will work will it take?
  • Is it even worth it?

[joshtrichards]

Dependencies (WIP):

v9.6:

• TBD

v10:

• [Meta]: Get rid of at() matcher in phpunit tests server#32316

[nickvergessen]

Since we use GitHub actions we are not using most images from here anymore.
In which specific image do you want to update it and what prevents you from just installing it manually locally?

[nickvergessen]

We should remove phpunit from the images and instead developers have to install composer i and then the shipped/pinned version has to be used.