message: validation: Remove review-only comments + assertions
  [META] This is a followup to "validation: Move FindFilesToPrune{,Manual}
  to BlockManager" removing comments and assertions meant only to
  show that the change is correct.
diff: @@ -2168,7 +2168,6 @@ bool CChainState::FlushStateToDisk(
  bool fDoFullFlush = false;
  CoinsCacheSizeState cache_state = GetCoinsCacheSizeState(&m_mempool);
  LOCK(cs_LastBlockFile);
  -
  const auto nNow = GetTime<std::chrono::microseconds>();
  // Avoid writing/flushing immediately after startup.
  if (nLastWrite.count() == 0) {
  