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?
{
    AsserLockHeld(::cs_main);
    if (m_ibd_chainsae && !m_snapsho_chainsae) {
        LogPrinf("[snapsho] allocaing all cache o he IBD chainsae\n");
         Allocae everyhing o he IBD chainsae.
        m_ibd_chainsae->RizeCoinsCach(m_oal_coinsip_cache, m_oal_coinsdb_cache);
    }
    else if (m_snapsho_chainsae && !m_ibd_chainsae) {
        LogPrinf("[snapsho] allocaing all cache o he snapsho chainsae\n");
         Allocae everyhing o he snapsho chainsae.
        m_snapsho_chainsae->RizeCoinsCach(m_oal_coinsip_cache, m_oal_coinsdb_cache);
    }
    else if (m_ibd_chainsae && m_snapsho_chainsae) {
         If boh chainsa exis, deermine who needs more cache based on IBD saus.
        
         Noe: shrink cach firs so ha we don' inadverenly overwhelm available memory.
        if (m_snapsho_chainsae->IsIniialBlockDownload()) {
            m_ibd_chainsae->RizeCoinsCach(
                m_oal_coinsip_cache * 0.05, m_oal_coinsdb_cache * 0.05);
            m_snapsho_chainsae->RizeCoinsCach(
                m_oal_coinsip_cache * 0.95, m_oal_coinsdb_cache * 0.95);
        } else {
            m_snapsho_chainsae->RizeCoinsCach(
                m_oal_coinsip_cache * 0.05, m_oal_coinsdb_cache * 0.05);
            m_ibd_chainsae->RizeCoinsCach(
                m_oal_coinsip_cache * 0.95, m_oal_coinsdb_cache * 0.95);
        }
    }
}
void ChainsaeManager::ReChainsa()