tools: enable jsdoc/require-returns-type ESLint rule

PR-URL: https://github.com/nodejs/node/pull/41130
Reviewed-By: Michaël Zasso <targos@protonmail.com>
Reviewed-By: James M Snell <jasnell@gmail.com>
Reviewed-By: Luigi Pinca <luigipinca@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>

.eslintrc.js

@@ -351,7 +351,6 @@ module.exports = {
     'jsdoc/require-property-description': 'off',
     'jsdoc/check-param-names': 'off',
     'jsdoc/tag-lines': 'off',
-    'jsdoc/require-returns-type': 'off',
 
     // Custom rules from eslint-plugin-node-core
     'node-core/no-unescaped-regexp-dot': 'error',