The error happens when the wallet has some locked outputs in
`listlockunspent` and the corresponding `gettransaction` doesn't contain
the details of this particular output.

It may be related to bitcoin/bitcoin#28555. It
is at least the same symptom.

The locked outputs were locked by creating a transaction in Specter.
This has happened to me multiple times.

The UI says it failed to load the wallet with the following error:
Failed to load utxos, IndexError: list index out of range

The raw transaction does contain the missing output so we use that
instead.

Here's an example that generates the error:
listlockunspent:
[
  {
    "txid": "<some txid>",
    "vout": 0
  }
]

gettransaction <some txid>:
{
  "amount": <redacted>,
  "fee": <redacted>,
  "confirmations": <redacted>,
  "blockhash": "<redacted>",
  "blockheight": <redacted>,
  "blockindex": <redacted>,
  "blocktime": <redacted>,
  "txid": "<some tx id>",
  "wtxid": "<redacted>",
  "walletconflicts": [
  ],
  "time": <redacted>,
  "timereceived": <redacted>,
  "bip125-replaceable": "no",
  "details": [
    {
      "address": "<redacted>",
      "category": "send",
      "amount": <redacted>,
      "label": "<redacted>",
      "vout": 1,
      "fee": <redacted>,
      "abandoned": false
    }
  ],
  "hex": "<some raw tx hex>",
  "lastprocessedblock": {
    "hash": "<redacted>",
    "height": <redacted>
  }
}

decoderawtransaction <some raw tx hex>:
{
  "txid": "<some txid>",
  "hash": "<redacted>",
  "version": 2,
  "size": <redacted>,
  "vsize": <redacted>,
  "weight": <redacted>,
  "locktime": <redacted>,
  "vin": [
    {
      "txid": "<some other txid>",
      "vout": 0,
      "scriptSig": {
        "asm": "",
        "hex": ""
      },
      "txinwitness": [
        "<redacted>",
        "<redacted>"
      ],
      "sequence": <redacted>
    }
  ],
  "vout": [
    {
      "value": <redacted>,
      "n": 0,
      "scriptPubKey": {
        "asm": "<redacted>",
        "desc": "<redacted>",
        "hex": "<redacted>",
        "address": "<redacted>",
        "type": "<redacted>"
      }
    },
    {
      "value": <redacted>,
      "n": 1,
      "scriptPubKey": {
        "asm": "<redacted>",
        "desc": "<redacted>",
        "hex": "<redacted>",
        "address": "<redacted>",
        "type": "<redacted>"
      }
    }
  ]
}

Because the decoderawtransaction RPC is not available in Spectrum and
the tools to decode the raw transaction are already there.