Remove Roster object caching to fix Laravel 13 serialization issue

[pushpak1300]

Laravel 13 adds serializable_classes => false in config/cache.php, which prevents PHP from unserializing arbitrary objects from the cache. This causes the cached Roster object to come back as __PHP_Incomplete_Class, breaking Boost.

Approach

• Remove the cache layer entirely — the Roster singleton already ensures scanning only happens once per request, and the cost of re-parsing lock files is already very minimal