Leave default args to empty string

jira/client.py

@@ -2959,19 +2959,19 @@ def delete_user_avatar(self, username: str, avatar: str):
 
     def search_users(
         self,
-        user: Optional[str] = None,
+        user: str = "",
         startAt: int = 0,
         maxResults: int = 50,
         includeActive: bool = True,
         includeInactive: bool = False,
-        query: Optional[str] = None,
+        query: str = "",
     ) -> ResultList[User]:
         """Get a list of user Resources that match the specified search string.
         "username" query parameter is deprecated in Jira Cloud; the expected parameter now is "query", which can just be the full
         email again. But the first parameter is kept for backwards compatibility.
 
         Args:
-            user (optional str): a string to match usernames, name or email against.
+            user (str): a string to match usernames, name or email against.
             startAt (int): index of the first user to return.
             maxResults (int): maximum number of users to return.
               If maxResults evaluates as False, it will try to get all items in batches.