bugfix: cad/cura remove NoKeyringError from import

py-keyring is stacked at 18.0.1 at the moment. cura expects 23.0.1,
which has NoKeyringError. until 23.0.1 is available again, remove it.

ImportError: cannot import name 'NoKeyringError' from 'keyring.errors'
(/usr/local/lib/python3.8/site-packages/keyring/errors.py)

https://www.freshports.org/security/py-keyring/

cad/cura/files/patch-cura_OAuth2_KeyringAttribute.py

@@ -0,0 +1,11 @@
+--- cura/OAuth2/KeyringAttribute.py.orig	2022-04-28 04:59:10 UTC
++++ cura/OAuth2/KeyringAttribute.py
+@@ -5,7 +5,7 @@ from typing import Type, TYPE_CHECKING, Optional, List
+ from io import BlockingIOError
+ import keyring
+ from keyring.backend import KeyringBackend
+-from keyring.errors import NoKeyringError, PasswordSetError, KeyringLocked
++from keyring.errors import PasswordSetError, KeyringLocked
+
+ from UM.Logger import Logger
+