Add return types for DependencyInjection functions to remove deprectations messages

[DennisdeBest]

In symfony 6.3 deprecation messages like :

Method "Symfony\Component\DependencyInjection\Compiler\CompilerPassInterface::process()" might add "void" as a native return type declaration in the future. Do the same in implementation "Omines\DataTablesBundle\DependencyInjection\Compiler\LocatorRegistrationPass" now to avoid errors or add an explicit @return annotation to suppress this message.

were added, I added the return types for the two classes that generated the deprecation messages.

[curry684]

Thanks :)