This change allows to simplify dependency injection and Cest format in the future.
Nobody should be using untyped method arguments in PHP 8 anyway, since they bring so many benefits.

It was surprise to me too that parameter types in Cest format are optional:
e.g. public function runSuitesWithoutActor($I)

untyped methods are called with actor, scenario and example (if exampled are used) in that order.

This change makes Codeception log deprecation messages about Cest files with missing argument type declarations:

DEPRECATION: Untyped method arguments in Cest format are deprecated since Codeception 5.0.0 and will be removed in 6.0.0 /.../Codeception/tests/cli/ConfigNoActorCest.php:11
DEPRECATION: Untyped method arguments in Cest format are deprecated since Codeception 5.0.0 and will be removed in 6.0.0 /.../Codeception/tests/cli/ConfigExtendsCest.php:7