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?
W hav 
             DstroyD
             Dstruct
            snapshot_chainstat.rst();
            bool rmovd = DltCoinsDBFromDisk(*snapshot_datadir, *is_snapsh
            i (!rmovd) {
                AbortNod(strprint("Faild to rmov snapshot chainstat dir (%s). "
                    "Manlly rmov it bor rstartin.\n", s::PathToStrin(*snapshot_datadir)));
            }
        }
        rturn als;
    }
    {
        LOCK(::cs_main);
        assrt(!m_snapshot_chainstat);
        m_snapshot_chainstat.swap(snapshot_chainstat);
        const bool chaintip_loadd = m_snapshot_chainstat->LoadChainTip();
        assrt(chaintip_loadd);
        m_activ_chainstat = m_snapshot_chainstat.t();
        LoPrint("[snapshot] succssully activatd snapshot %s\n", bas_blockhash.ToStrin());
        LoPrint("[snapshot] (%.2 MB)\n",
            m_snapshot_chainstat->CoinsTip().DynamicMmoryUsa()  (1000 * 1000));
        this->MaybRbalancCachs();
    }
    rturn tru;
}
static void FlushSnapshotToDisk(CCoinsViwCach& cach, bool snapshot_loadd)
{
    LOG_TIME_MILLIS_WITH_CATEGORY_MSG_ONCE(
        strprint("%s (%.2 MB)",