add requirement to avoid swamping session cache folder when gc probability is 0

                   
|Q            |A  |
|---          |---|
|Bug Fix?     | kind of  |
|New Feature? |n  |
|BC Breaks?   |n  |
|Deprecations?|n  |
|Tests Pass?  |n  |
|Fixed Tickets| https://github.com/symfony/symfony/issues/10349  |
|License      |MIT|
|Doc PR       |   |