feat(php): drop support for EOLed PHP versions and unify min required version

[simPod]

Anything under php v8.1 is EOLed.

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[simPod]

@jebentier (2017/07), @dkarlovi (2017/07), @mandrean (2017/08), @jfastnacht (2017/09), @ybelenko (2018/07), @renepardon (2018/12)

[wing328]

as discussed, we will include this change in the upcoming v8.0.0 major release later.

[wing328]

thanks for the PR. just merged it to the master

if anyone needs a rollback for whatever reason, we will consider adding an option.

[simPod]

Cool thanks! Old versions still support dead PHPs, anyone can use those.

I planed some improvements for php in the past, will try to remember what those were and send PR eventually.