[FIX] base_setup: test checking config links

The tag "nightly" is not an actual thing, so the test gets run all the
time, and since the taxcloud page has been moved it now breaks.

Replace by the proper tag.

closes odoo/odoo#46938

Related: odoo/enterprise#9019

addons/base_setup/tests/test_res_config_doc_links.py

@@ -5,7 +5,7 @@ from odoo.tests.common import HttpCase, tagged
 import re
 
 
-@tagged('nightly', 'post_install', '-at_install')
+@tagged('-standard', 'external', 'post_install', '-at_install') # nightly is not a real tag
 class TestResConfigDocLinks(HttpCase):
     """
     Parse the 'res_config' view to extract all documentation links and