Fix retry_on_error type annotation (#446)

Co-authored-by: Victorien <65306057+Viicos@users.noreply.github.com>

Author: armicron

arq/connections.py

@@ -50,7 +50,7 @@ class RedisSettings:
     sentinel_master: str = 'mymaster'
 
     retry_on_timeout: bool = False
-    retry_on_error: Optional[list[Exception]] = None
+    retry_on_error: Optional[list[type[Exception]]] = None
     retry: Optional[Retry] = None
 
     @classmethod