The experimental Sylius\Bundle\ApiBundle\Behat\Extension\SyliusApiBundleExtension
and its Sylius\Bundle\ApiBundle\Behat\Tester\ApiScenarioEventDispatchingScenarioTester
are using some Behat symbols and Behat is, of course, not required.
I don't know if this experimental ApiBundle extension is used or
not. Anyway this MUST be fixed.
Sylius\Bundle\CoreBundle\EventListener\CircularDependencyBreakingExceptionListener
uses two class from symfony/http-kernel that have been removed in
version 5.
So currently Sylius it's not really compatible with both
symfony/http-kernel 4 and 4: this MUST be fixed.