fix: Fix PHPStan errors on level 9

[siketyan]

Fixed some errors on PHPStan level 9.

As Is:

❯ vendor/bin/phpstan analyse src --level 9 Note: Using configuration file /Users/siketyan/.local/src/github.com/phpstan/phpstan-symfony/phpstan.neon. 54/54 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100% ------ ------------------------------------------------------------------------------------------------------------------ Line Symfony/Configuration.php ------ ------------------------------------------------------------------------------------------------------------------ 21 Method PHPStan\Symfony\Configuration::getContainerXmlPath() should return string|null but returns mixed. 26 Method PHPStan\Symfony\Configuration::hasConstantHassers() should return bool but returns mixed. 31 Method PHPStan\Symfony\Configuration::getConsoleApplicationLoader() should return string|null but returns mixed. ------ ------------------------------------------------------------------------------------------------------------------ ------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------- Line Type/Symfony/ParameterDynamicReturnTypeExtension.php ------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------- 166 Parameter #2 $value of method PHPStan\Type\Symfony\ParameterDynamicReturnTypeExtension::generalizeTypeFromValue() expects array|bool|float|int|string, mixed given. 177 Parameter #2 $value of method PHPStan\Type\Symfony\ParameterDynamicReturnTypeExtension::generalizeTypeFromValue() expects array|bool|float|int|string, mixed given. ------ --------------------------------------------------------------------------------------------------------------------------------------------------------------------- [ERROR] Found 5 errors 

To Be:

❯ vendor/bin/phpstan analyse src --level 9 Note: Using configuration file /Users/siketyan/.local/src/github.com/phpstan/phpstan-symfony/phpstan.neon. 54/54 [▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓▓] 100% [OK] No errors