Move ESLint config file to tooling directory

.eslintrc.yml

@@ -3,7 +3,7 @@ extends:
   - plugin:@gitlab/i18n
   - plugin:no-jquery/slim
   - plugin:no-jquery/deprecated-3.4
-  - ./config/eslint-config-ignore-ee.js
+  - ./tooling/eslint-config/conditionally_ignore_ee.js
 globals:
   __webpack_public_path__: true
   gl: false

tooling/README.md

+# Tooling
+
+This directory contains tools and configuration for development only.
+

config/eslint-config-ignore-ee.js → tooling/eslint-config/conditionally_ignore_ee.js

-const IS_EE = require('./helpers/is_ee_env');
+/* eslint-disable import/no-commonjs */
+
+const IS_EE = require('../../config/helpers/is_ee_env');
 
 module.exports = IS_EE ? {} : { ignorePatterns: ['ee/**/*.*'] };