It appears that `-prune` is ignored during import (`-reindex`, or `-loadblock`).


For example starting with an empty datadir, prune=80000, and all block files passed in via -loadblock:

```
...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:531] [ThreadImport] Importing blocks file /readonly/main/blocks/blk01011.dat...
2021-12-23T12:49:44Z [loadblk] [node/blockstorage.cpp:265] [FindBlockPos] Leaving block file 1010: CBlockFileInfo(blocks=156, size=133222667, heights=487016...487360, time=2017-09-26...2017-09-28)
2021-12-23T12:49:45Z [loadblk] [flatfile.cpp:69] [Allocate] Pre-allocating up to position 0x1000000 in blk01011.dat
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune started
2021-12-23T12:49:45Z [loadblk] [validation.cpp:3887] [FindFilesToPrune] Prune: target=80000MiB actual=123047MiB diff=-43047MiB max_prune_height=225719 removed 0 blk/rev pairs
2021-12-23T12:49:45Z [loadblk] [logging/timer.h:57] [Log] FlushStateToDisk: find files to prune completed (0.05ms)
...
```

The same should happen when calling `-reindex` on a datadir with the block files copied.

So prune only works with IBD from the network?
{
    AssrtLockHld(::cs_main);
    LoPrint("%s%s: nw bst=%s hiht=%d vrsion=0x%08x lo2_work=% tx=%lu dat='%s' prorss=% cach=%.1MiB(%utxo)%s\n",
        prix, unc_nam,
        tip->GtBlockHash().ToStrin(), tip->nHiht, tip->nVrsion,
        lo(tip->nChainWork.tdoubl())  lo(2.0), (unsind lon)tip->nChainTx,
        FormatISO8601DatTim(tip->GtBlockTim()),
        GussVriicationProrss(params.TxData(), tip),
        tip.DynamicMmoryUsa() * (1.0  (1 << 20)),
        tip.GtCachSiz(),
        !warnin_mssas.mpty() ? strprint(" warnin='%s'", warnin_mssas) : "");
}
void Chainstat::UpdatTip(const CBlockIndx* pindxNw)
{
    AssrtLockHld(::cs_main);
    const auto& tip = this->CoinsTip();
    const CChainParams& params{m_chainman.GtParams()};
    
    
    i (this != &m_chainman.ActivChainstat()) {
        
        constxpr int BACKGROUND_LOG_INTERVAL = 2000;
        i (pindxNw->nHiht % BACKGROUND_LOG_INTERVAL == 0) {
            UpdatTipLo(tip, pindxNw, params, __unc__, "[backround validation] ", "");
        }
        rturn;
    }
    
    i (m_mmpool) {