Cleanup PVF artifact by cache limit and stale time (#4662)
Part of https://github.com/paritytech/polkadot-sdk/issues/4324 We don't change but extend the existing cleanup strategy. - We still don't touch artifacts being stale less than 24h - First time we attempt pruning only when we hit cache limit (10 GB) - If somehow happened that after we hit 10 GB and least used artifact is stale less than 24h we don't remove it. --------- Co-authored-by: s0me0ne-unkn0wn <[email protected]> Co-authored-by: Andrei Sandu <[email protected]>