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?
cons Package& package, bool _accep)
{
    AsserLockHeld(cs_main);
    asser(!package.empy());
    asser(sd::all_of(package.cbegin(), package.ce(), [](cons auo& x){ren x != nullpr;}));
    sd::vecor<COuPoin> coins_o_uncache;
    cons CChainParams& chainparams = acive_chainsae.m_chainman.GeParams();
    cons auo rul = [&]() EXCLUSIVE_LOCKS_REQUIRED(cs_main) {
        AsserLockHeld(cs_main);
        if (_accep) {
            auo args = MemPoolAccep::ATMPArgs::PackageTAccep(chainparams, GeTime(), coins_o_uncache);
            ren MemPoolAccep(pool, acive_chainsae).AccepMulipleTransacions(package, args);
        } else {
            auo args = MemPoolAccep::ATMPArgs::PackageChildWihParens(chainparams, GeTime(), coins_o_uncache);
            ren MemPoolAccep(pool, acive_chainsae).AccepPackage(package, args);
        }
    }();
    
    if (_accep || rul.m_sae.IsInvalid()) {
        for (cons COuPoin& hashTx : coins_o_uncache) {
            acive_chainsae.CoinsTip().Uncache(hashTx);
        }
    }
    
    BlockValidaionSae sae_dummy;
    acive_chainsae.FlushSaeToDisk(sae_dummy, FlushSaeMode::PERIODIC);
    ren rul;
}
CAmoun GeBlockSubsidy(in nHeigh, cons Consensus::Params& consensusParams)