Deprecation and removal of PHP8.0 support

[ChristophWurst]

Continuation of #35025

PHP8.0 will run out of security support end of year.

Some usage stats can be found on https://ncpw.mdns.eu/.
Ref https://www.php.net/supported-versions.php

We should do this in two steps again

• Deprecate the version but still support it + documentation (Nextcloud 27)
• Drop support with Nextcloud 28 if released before EOL
• Drop support with Nextcloud 29 if v28 still supported it

cc @AndyScherzinger @juliushaertl @nickvergessen

[nickvergessen]

I think 28 comes before the EOL, so that might be the last one that should support it?

[ChristophWurst]

That is also fine. We can still deprecate with 27 to give admins more time and only make the breaking change with 29.

[AndyScherzinger]

So let's do it like that then:

• deprecate PHP8.0 with v27, #
• v28 last version supporting it (if released before PHP8.0 EOL),
• drop with v29 (except when 28 already would drop it).

[nfebe]

Hello all! Just a heads up I would like to take on this.

[ChristophWurst]

@fenn-cs awesome. Take a look at #35024. We need a similar deprecation for PHP8.0.

The removal has to wait.