Fix tests on Python 3.12

We were seeing the following test failures on Python 3.12:

  openstackclient.tests.unit.common.test_module.TestModuleList.test_module_list_all
  openstackclient.tests.unit.common.test_module.TestModuleList.test_module_list_no_options

Both failures were caused by missing attributes of 'sys', e.g.

  AttributeError: module 'sys' has no attribute 'builtin_module_names'

Fix this by exposing the real 'sys' module as part of our mock of
'sys.modules'.

Change-Id: I17391a46f08896f49dccaf75ad685dab1375a03d
Signed-off-by: Stephen Finucane <stephenfin@redhat.com>

Author: stephenfin

openstackclient/tests/unit/common/test_module.py

@@ -15,6 +15,7 @@
 
 """Test module module"""
 
+import sys
 from unittest import mock
 
 from openstackclient.common import module as osc_module
@@ -43,6 +44,7 @@
 module_version_5 = '0.0.1'
 
 MODULES = {
+    'sys': sys,
     module_name_1: fakes.FakeModule(module_name_1, module_version_1),
     module_name_2: fakes.FakeModule(module_name_2, module_version_2),
     module_name_3: fakes.FakeModule(module_name_3, module_version_3),