PSync

We have observed cases where a pair of nodes can get into a "loop" with cached sync data, constantly fulfilling an unchanged sync reply from the ContentStore due to the need to always have a sync interest pending which can lead to random unnecessary spikes in interests. A potential mitigation is to simply avoid caching sync data altogether by adjusting the data freshness to be an arbitrarily small value to avoid causing these problems, as there's no obvious benefit to caching these data