utxoset table unexpectedly large

### Issue and Steps to Reproduce
From the CLN Discord server, support channel:

1) utxoset table is ~180MB
2) entire db is ~430MB, but this is unaccounted for in the table data somehow

This node has never been connected to any peers as far as I know, and has never had any funds in its wallet. It basically just synced the chain and I've used it for dev stuff. What on earth might we need ~180MB of utxos for?

### `getinfo` output
```
$ lightning-cli getinfo
{
"id": "<>",
"alias": "<>",
"color": "<>",
"num_peers": 0,
"num_pending_channels": 0,
"num_active_channels": 0,
"num_inactive_channels": 0,
"address": [],
"binding": [
{
"type": "ipv4",
"address": "127.0.0.1",
"port": 9735
}
],
"version": "v23.08",
"blockheight": 815163,
"network": "bitcoin",
"fees_collected_msat": 0,
"lightning-dir": "/var/lib/clightning/bitcoin",
"our_features": {
"init": "08a0802a0a69a2",
"node": "88a0802a0a69a2",
"channel": "",
"invoice": "02000022024100"
}
}
```