collection.remove has been removed in pymongo >=4

src/saml2/mongo_store.py

@@ -99,7 +99,7 @@ def remove_authn_statements(self, name_id):
         logger.debug("remove authn about: %s", name_id)
         key = sha1(code_binary(name_id)).hexdigest()
         for item in self.assertion.find({"name_id_key": key}):
-            self.assertion.remove(item["_id"])
+            self.assertion.delete_one(item["_id"])
 
     def get_authn_statements(self, name_id, session_index=None, requested_context=None):
         """