fix(env): 🐛 Update Shaka-Packager binary retrieval method

* Changed the binary retrieval for `Shaka-Packager` to use `find_binary` for improved accuracy.
* This ensures the correct binary is located and used in the environment checks.

unshackle/core/proxies/surfsharkvpn.py

@@ -1,6 +1,6 @@
 import json
-import re
 import random
+import re
 from typing import Optional
 
 import requests