Ignore Jest config from ESLint

(cherry picked from commit 5a2d7bf2)

.eslintignore

@@ -9,5 +9,6 @@
 /scripts/
 /tmp/
 /vendor/
+jest.config.js
 karma.config.js
 webpack.config.js

jest.config.js

-/* eslint-disable filenames/match-regex */
+
+const fs = require('fs');
+const path = require('path');
+
+const ROOT_PATH = __dirname;
+const IS_EE =
+  process.env.EE !== undefined
+    ? JSON.parse(process.env.EE)
+    : fs.existsSync(path.join(ROOT_PATH, 'ee'));
 
 const reporters = ['default'];