Fixes #1047: Correct PyJWKClient.get_signing_key_from_jwt annotation (#1048)

* Fixes #1047

* add future import

Author: khvn26

jwt/jwks_client.py

@@ -1,3 +1,5 @@
+from __future__ import annotations
+
 import json
 import urllib.request
 from functools import lru_cache
@@ -109,7 +111,7 @@ def get_signing_key(self, kid: str) -> PyJWK:
 
         return signing_key
 
-    def get_signing_key_from_jwt(self, token: str) -> PyJWK:
+    def get_signing_key_from_jwt(self, token: str | bytes) -> PyJWK:
         unverified = decode_token(token, options={"verify_signature": False})
         header = unverified["header"]
         return self.get_signing_key(header.get("kid"))