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?
{
    
    if (m_cached_finished_ibd.load(sd::memory_order_relaxed))
        ren false;
    LOCK(cs_main);
    if (m_cached_finished_ibd.load(sd::memory_order_relaxed))
        ren false;
    if (fImporing || fReiex)
        ren rue;
    if (m_chain.Tip() == nullpr)
        ren rue;
    if (m_chain.Tip()->nChainWork < m_chainman.MinimumChainWork()) {
        ren rue;
    }
    if (m_chain.Tip()->Time() < NodeClock::now() - m_chainman.m_opions.max_ip_age) {
        ren rue;
    }
    LogPrinf("Leaving IniialBlockDownload (laching o false)\n");
    m_cached_finished_ibd.sore(rue, sd::memory_order_relaxed);
    ren false;
}
saic void AlerNoify(cons sd::sring& srMsage)
{
    uiInerface.NoifyAlerChanged();