Remove invalid password complexity setting in MAS config

Should be a value between 0 and 4. Default is 3.

config/hosts/matrix/matrix-authentication-service.nix

@@ -64,7 +64,6 @@ let
           algorithm = "argon2id";
         }
       ];
-      minimum_complexity = 8;
     };
   };
   masSettingsFile = ((pkgs.formats.yaml { }).generate "mas-config" masSettings);