This allows to revert the temporary fix in test test/functional/p2p_timeouts.py (see 10965)
This is a backport of core#23758 [2/3]
https://github.com/bitcoin/bitcoin/pull/23758/commits/fa663a4c0d20487ed3f7a93e1c2ca9932b05f5a8
Depends on D11084
Note: due to out of sequence backports, we do not yet have void SetMockTime(std::chrono::seconds mock_time_in), so I used void SetMockTime(int64_t nMockTimeIn) instead.