fix: detect case-sensitive filesystems correctly under yarn PnP

yarn in PnP mode uses a virtual filesystem, and adding the `preferUnplugged: true` flag forces it to write this package to the real filesystem. This is needed so the case-sensitive detection logic in `resolve.js` works properly.

Author: charlessuh

utils/package.json

@@ -21,6 +21,7 @@
   ],
   "author": "Ben Mosher <me@benmosher.com>",
   "license": "MIT",
+  "preferUnplugged": true,
   "bugs": {
     "url": "https://github.com/import-js/eslint-plugin-import/issues"
   },