[BC break] Exception thrown when "session save path is ignored without a handler service" #32837
Description
Symfony version(s) affected: 3.4.30
Description
Upon update from 3.4.29 to 3.4.30 a new exception is being thrown by framework bundle when save_path is used at framework.session when handler is set to null. This breaks previously working config (site doesn't use sessions).
It was introduced here: #31620
How to reproduce
https://github.com/phpdocker-io/phpdocker.io/blob/master/app/config/config.yml#L30
That was IIRC default config. Site doesn't use sessions.
Possible Solution
Remove the LogicException and instead throw a deprecation warning.