refactor(anvil): flip filter expiration timestamp

[mattsse]

Motivation

flip logic how filters are evicted, instead of now they now store their expiration deadline.

this is the only time we use Instant::now -Duration but is unlikely the reason for #2685
Ther was an tokio::time::interval that internally uses substraction

apparently there can be some inconsitencies with Instant + Systemtimestamp+ system boot: rust-lang/rust#48980

Solution

convert now - dur to now + dur

Closes #2685

• use interval_at instead of interval