Bug: Assigning an immediately-expired value to an existing TLRUCache key silently retains the stale old value

Bug: Assigning an immediately-expired value to an existing TLRUCache key silently retains the stale old value: a task in Repo2RLEnv R2E-Gym / SWEGEN (Harbor dataset). When a key already exists in a TLRUCache and you overwrite it with a value whose TTU (time-to-use) is already expired (i.e., ttu…

The task

When a key already exists in a `TLRUCache` and you overwrite it with a value whose TTU (time-to-use) is already expired (i.e., `ttu` returns a time not greater than the current time), the cache silently ignores the assignment and keeps the old value instead of evicting the key.

Part of FineEnvs/repo2rlenv-r2e-gym.