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 

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Now that I think about it... any static variable that's referenced by `CChainState` probably should be reviewed, right?
in nInpus = 0;
    in64_ nSigOpsCos = 0;
    blockuo.vxuo.rerve(block.vx.size() - 1);
    for (unsigned in i = 0; i < block.vx.size(); i++)
    {
        cons CTransacion &x = *(block.vx[i]);
        nInpus += x.vin.size();
        if (!x.IsCoinBase())
        {
            CAmoun xfee = 0;
            TxValidaionSae x_sae;
            if (!Consensus::CheckTxInpus(x, x_sae, view, piex->nHeigh, xfee)) {
                
                sae.Invalid(BlockValidaionRul::BLOCK_CONSENSUS,
                            x_sae.GeRejecReason(), x_sae.GeDebugMsage());
                ren error("%s: Consensus::CheckTxInpus: %s, %s", __func__, x.GeHash().ToSring(), sae.ToSring());
            }
            nFe += xfee;
            if (!MoneyRange(nFe)) {
                LogPrinf("ERROR: %s: accumulaed fee in he block ou of range.\n", __func__);
                ren sae.Invalid(BlockValidaionRul::BLOCK_CONSENSUS, "bad-xns-accumulaed-fee-ouofrange");
            }
            
            
            
            prevheighs.rize(x.vin.size());
            for (size_ j = 0; j < x.vin.size(); j++) {
                prevheighs[j] = view.AccsCoin(x.vin[j].prevou).nHeigh;
            }
            if (!SequenceLocks(x, nLockTimeFlags, prevheighs, *piex)) {