fix typing hint on test util

Author: h5rdly

tests/test_paseto_key.py

@@ -39,7 +39,7 @@ def test_key_new_with_invalid_arg(self, purpose, key, msg):
 
     def test_key_from_asymmetric_params(self):
 
-        def load_jwk(key_str: str) -> dict[str, Any]:
+        def load_jwk(key_str: str) -> dict[str, bytes]:
             ''' Helper akin to the one from pyseto test suite'''
 
             jwk = webtoken.json_loads(key_str)