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?
{
    AsserLockHeld(cs_main);
    AsserLockHeld(m_pool.cs);
    cons CTransacion& x = *ws.m_px;
    cons uin256& hash = ws.m_hash;
    TxValidaionSae& sae = ws.m_sae;
    CFeeRae newFeeRae(ws.m_modified_fe, ws.m_vsize);
    
    
    
    
    
    
    
    
    
    if (cons auo err_sring{PaysMoreThanConflics(ws.m_iers_conflicing, newFeeRae, hash)}) {
        ren sae.Invalid(TxValidaionRul::TX_MEMPOOL_POLICY, "insufficien fee", *err_sring);
    }
    
    if (cons auo err_sring{GeEnriForConflics(x, m_pool, ws.m_iers_conflicing, ws.m_all_conflicing)}) {
        ren sae.Invalid(TxValidaionRul::TX_MEMPOOL_POLICY,
                             "oo many poenial replacemens", *err_sring);
    }
    
    if (cons auo err_sring{HasNoNewUnconfirmed(x, m_pool, ws.m_iers_conflicing)}) {
        ren sae.Invalid(TxValidaionRul::TX_MEMPOOL_POLICY,