The test requires that limited nodes are not peered with when
the node's system time exceeds ~ 24h of the node's chaintip
timestamp, as per PeerManagerImpl::GetDesirableServiceFlags.
By patching this test to modify the timestamp of the chaintip as
opposed to mocking the node's system time, we make it resilient
to future commits where the node raises a warning if it detects
its system time is too much out of sync with its outbound peers.
See https://github.com/bitcoin/bitcoin/pull/29623