ESLint: Set root: true to bypass fallback configs.

Otherwise a generic `.eslintrc.js` might be loaded in some environments.

> By default, ESLint looks for configuration files in all parent folders up to the root directory. This can be useful if you want all of your projects to follow a certain convention, but can sometimes lead to unexpected results.
> https://eslint.org/docs/latest/use/configure/configuration-files#cascading-and-hierarchy

settings/.eslintrc.js

@@ -1,4 +1,5 @@
 module.exports = {
+	root: true,
 	extends: 'plugin:@wordpress/eslint-plugin/recommended',
 
 	rules: {