Fix some spelling and broken code snippets. (#18791)

Configure default session.gc_maxlifetime as lifetime of the session i…

…f Session.timeout configuration isn't set (#18670)

* Configure default session.gc_maxlifetime as lifetime of the session if Session.timeout configuration isn't set

* Add test to assert lifeTime value is set to default php ini value

Update phpstan

Drop psalm

Drop psalm

Fixed typos and cleanup.

Merge branch '5.x' into 5.next

Merge branch '5.x' into 5.next

Don't overwrite content body when request data is empty (#18182)

Apply suggestions from code review

Co-authored-by: Kevin Pfeifer <info@pfiff.me>