lint/src/util: fix TS2314

Fix error in lint:

> lint/src/util/structure.ts:16:20 - error TS2314: Generic type 'RuleMetaData<MessageIds, Options>' requires 2 type argument(s).
>
> 16 export type Meta = RuleMetaData<string>;

Author: alanorth

lint/src/util/structure.ts

@@ -13,7 +13,7 @@ import {
 } from '@typescript-eslint/utils/ts-eslint';
 import { EnumType } from 'typescript';
 
-export type Meta = RuleMetaData<string>;
+export type Meta = RuleMetaData<string, unknown[]>;
 export type Valid = ValidTestCase<unknown[]>;
 export type Invalid = InvalidTestCase<string, unknown[]>;