Error: contact maintainers [unknown type]: undefined

this is my contract generate code info:
```
$ cosmwasm-ts-codegen generate \
--plugin client \
--schema ./schema \
--out ./ts \
--name AMaci
? [bundle] enable bundle? No

Error: contact maintainers [unknown type]: undefined
at getType (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:261:13)
at getArrayTypeFromItems (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:95:24)
at getArrayTypeFromItems (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:91:28)
at getTypeInfo (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:168:18)
at getPropertyType (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:283:18)
at getPropertySignatureFromProp (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:361:5)
at /Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:386:12
at Array.map ()
at getParamsTypeAnnotation (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:385:26)
at createTypedObjectParams (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:426:24)
{
"type": "object",
"required": [
"deactivate_message"
],
"properties": {
"deactivate_message": {
"type": "array",
"items": {
"type": "array",
"items": {
"$ref": "#/definitions/Uint256"
}
}
}
},
"additionalProperties": false
} deactivate_message
/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:261
throw new Error('contact maintainers [unknown type]: ' + type);
^

Error: contact maintainers [unknown type]: undefined
at getType (/Users/feng/.nvm/versions/node/v18.12.1/lib/node_modules/@cosmwasm/ts-codegen/node_modules/wasm-ast-types/main/utils/types.js:261:13)
```

示されている cosmwasm-ts-codegen コマンドとスキーマで問題を再現し、その後 wasm-ast-types/main/utils/types.js の getType と getArrayTypeFromItems の周辺を調べます。Uint256 $ref を含むネストされた配列が unknown-type エラーなしで処理されることを確認し、生成を再実行して完了することを検証します。

索引モデルが issue の本文から書いたものです。