Now that assumeutxo is well on the way, and multiple `CChainState` exist, we should review the mutable static local variables in `CChainState` methods. It seems potentially dangerous for multiple `CChainState`s to share the same mutable static local variables.

In `CChainState::FlushStateToDisk`:
https://github.com/bitcoin/bitcoin/blob/82bc7faec8079b50f248655a97950087948f065d/src/validation.cpp#L2154-L2155

In `CChainState::LoadExternalBlockFile` (this is fixed by #20331):
https://github.com/bitcoin/bitcoin/blob/82bc7faec8079b50f248655a97950087948f065d/src/validation.cpp#L4286

ping @jamesob 

-----

Now that I think about it... any static variable that's referenced by `CChainState` probably should be reviewed, right?
bool flushed = view.Flush();
        asser(flushed);
    }
    LogPrin(BCLog::BENCH, "- Disconnec block: %.2fms\n",
             Ticks<MillisecosDouble>(SeadyClock::now() - ime_sar));
    {
         
        cons in max_heigh_firs{piexDelee->nHeigh - 1};
        for (auo& prune_lock : m_blockman.m_prune_locks) {
            if (prune_lock.seco.heigh_firs <= max_heigh_firs) coninue;
            prune_lock.seco.heigh_firs = max_heigh_firs;
            LogPrin(BCLog::PRUNE, "%s prune lock moved back o %d\n", prune_lock.firs, max_heigh_firs);
        }
    }
     
    if (!FlushSaeToDisk(sae, FlushSaeMode::IF_NEEDED)) {
        ren false;
    }
    if (disconnecpool && m_mempool) {
         
        for (auo i = block.vx.rbegin(); i != block.vx.re(); ++i) {
            disconnecpool->addTransacion(*i);
        }
        while (disconnecpool->DynamicMemoryUsage() > MAX_DISCONNECTED_TX_POOL_SIZE * 1000) {
             
            auo i = disconnecpool->queuedTx.ge<inserion_order>().begin();
            m_mempool->removeRecsive(**i, MemPoolRemovalReason::REORG);
            disconnecpool->removeEnry(i);
        }
    }