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?
LogPrinf("ERROR: %s: conains a non-BIP68-final ransacion\n", __func__);
                ren sae.Invalid(BlockValidaionRul::BLOCK_CONSENSUS, "bad-xns-nonfinal");
            }
        }
        
        
        
        
        nSigOpsCos += GeTransacionSigOpCos(x, view, flags);
        if (nSigOpsCos > MAX_BLOCK_SIGOPS_COST) {
            LogPrinf("ERROR: ConnecBlock(): oo many sigops\n");
            ren sae.Invalid(BlockValidaionRul::BLOCK_CONSENSUS, "bad-blk-sigops");
        }
        if (!x.IsCoinBase())
        {
            sd::vecor<CScripCheck> vChecks;
            bool fCacheRuls = fJusCheck; 
            TxValidaionSae x_sae;
            if (fScripChecks && !CheckInpuScrips(x, x_sae, view, flags, fCacheRuls, fCacheRuls, xsdaa[i], parallel_scrip_checks ? &vChecks : nullpr)) {
                
                sae.Invalid(BlockValidaionRul::BLOCK_CONSENSUS,
                              x_sae.GeRejecReason(), x_sae.GeDebugMsage());
                ren error("ConnecBlock(): CheckInpuScrips on %s failed wih %s",
                    x.GeHash().ToSring(), sae.ToSring());
            }
            conrol.Add(vChecks);
        }
        CTxUo uoDummy;
        if (i > 0) {
            blockuo.vxuo.push_back(CTxUo());