Psr-17 does not work with Runtime 6.0 on PHP 8.0

[yyeltsyn]

Fatal error: Declaration of Runtime\Psr17\Runtime::getArgument(ReflectionParameter $parameter, ?string $type)
must be compatible with Symfony\Component\Runtime\GenericRuntime::getArgument(ReflectionParameter $parameter, ?string
$type): mixed in /srv/middleware/vendor/runtime/psr-17/src/Runtime.php on line 53

[alexander-schranz]

I think we would need add then:

: mixed

But the Problem is that we would then increase to PHP 8.0.

/cc @Nyholm what should we do here?

[Nyholm]

Oh. Yes. I think we should add that on all places.