fix(eslint-plugin): use a default export for the rules type (#7266)

Author: bradzacher

packages/eslint-plugin/rules.d.ts

@@ -41,4 +41,4 @@ export interface TypeScriptESLintRules {
  [ruleName: string]: RuleModule<string, unknown[]>;
 }
 declare const rules: TypeScriptESLintRules;
-export = rules;
+export default rules;