2026-06-11

Migrate golang-lru v1 -> v2 across fbcode consumers

Summary: Adopts generic API (typed Get/Add, simplelru typed callback) for the simple LRU consumers. The three ARC users (fbtls, neteng/config_push/storage, neteng/transactional_config_management/storage) migrate to github.com/hashicorp/golang-lru/arc/v2, which is the v2 home for ARCCache. The typed v2 API lets us drop the interface{} type assertions at every Get site and the []interface{} -> []string conversion in fbtls' background sweep.

Reviewed By: leoleovich

Differential Revision: D108080824

fbshipit-source-id: 8472645e4ae32f1e95dbaa044d6c7eb5ab9775a4