Fix lint errors

Author: adamjmcgrath

src/auth0_server_python/auth_server/server_client.py

@@ -900,8 +900,8 @@ async def backchannel_authentication(
 
     async def initiate_backchannel_authentication(
             self,
-            options: Dict[str, Any]
-    ) -> Dict[str, Any]:
+            options: dict[str, Any]
+    ) -> dict[str, Any]:
         """
         Start backchannel authentication with Auth0.
 
@@ -1015,7 +1015,7 @@ async def initiate_backchannel_authentication(
                 e
             )
 
-    async def backchannel_authentication_grant(self, auth_req_id: str) -> Dict[str, Any]:
+    async def backchannel_authentication_grant(self, auth_req_id: str) -> dict[str, Any]:
         """
         Retrieves a token by exchanging an auth_req_id.
 

src/auth0_server_python/error/__init__.py

@@ -57,7 +57,7 @@ def __init__(self, code: str, message: str, interval: int | None, cause=None):
 
 class AccessTokenError(Auth0Error):
     """Error raised when there's an issue with access tokens."""
-    
+
     def __init__(self, code: str, message: str, cause=None):
         super().__init__(message)
         self.code = code

src/auth0_server_python/tests/test_server_client.py

@@ -1,5 +1,4 @@
 import json
-import pytest
 import time
 from unittest.mock import AsyncMock, MagicMock
 from urllib.parse import parse_qs, urlparse