chore: also test with PHP 8.3

[Croydon]

Why?

Test with all current NC versions + all PHP versions that are supported by all NC versions

https://github.com/nextcloud/server/wiki/Releases-and-PHP-versions

[Croydon]

All I wanted was to extend test coverage to current PHP and NC versions, but in order to get PHP 8.3 support, I needed to update php-cs-fixer from 3.35 to 3.75.

In those updates, php-cs-fixer has added an awful amount of new rules, so this ended in a formatting war.

I don't know how opinioned you are about formatting @pulsejet, and what your preferences are. Personally, I don't care that much when tools do the formatting job anyway.

I would suggest to just adopt whatever https://github.com/nextcloud/coding-standard/blob/master/src/Config.php is doing to have consistency with other Nextcloud code.

I will probably split out NC 31 CI coverage to another pull request to get that part of it faster in a mergeable state.

[Croydon]

I have splitted out test coverage for NC 31: #1436

[arnowelzel]

The standard for functions, classes and methods is to put the opening braces (curly brackets) in separate lines and not next to it. Also see the examples at https://www.php-fig.org/psr/psr-1/ and https://www.php-fig.org/psr/psr-12/.

Example - this is common practice:

class MyClass
{
    function myMethod()
    {
        $x = doSomething();
        if ($x < 5) {
            doSomethingElse();
        }
    }
}

But not this, because it is then harder to recognize the start of a method compared to the rest of the code:

class MyClass {
    function myMethod() {
        $x = doSomething();
        if ($x < 5) {
            doSomethingElse();
        }
    }
}

[Croydon]

Changes in this PR are either merged at this point or are no longer needed.

Closing in favor of #1502