Add getSession stub

[VincentLanglet]

Hi @seferov

There was the following discussion on phpstan-symfony phpstan/phpstan-symfony#233.

For 99% of the symfony users, $request->getSession() is returning a Session with the getFlashbag method which is not in SessionInterface. In the commit phpstan/phpstan-symfony@012305d, phpstan update the stub to make people life easier and avoiding the extract check instanceof Session.

I recommend psalm plugin to do the same because using both plugin gives the following issue.
-> without the check assert($session instanceof Session), psalm say the getFlashbag method doesn't exists
-> with the check, phpstan say the assert($session instanceof Session) check is always true.

[seferov]

@VincentLanglet Why exclude Symfony6 with PHP8?

[VincentLanglet]

It's currently a big failure because codeception doesn't support symfony 6.
https://github.com/Codeception/Codeception/blob/4.1/composer.json#L24

I can add back if you prefer, it will just mean the ci will always fail.

[seferov]

no problem, once codeception dependency is fixed, we can remove the ignore

[seferov]

For 99% of the symfony users, $request->getSession() is returning a Session with the getFlashbag method which is not in SessionInterface. In the commit phpstan/phpstan-symfony@012305d, phpstan update the stub to make people life easier and avoiding the extract check instanceof Session.

I recommend psalm plugin to do the same because using both plugin gives the following issue. -> without the check assert($session instanceof Session), psalm say the getFlashbag method doesn't exists -> with the check, phpstan say the assert($session instanceof Session) check is always true.

Thanks, looks good 👍