[FIX] hr_holidays: make ooo tests less dependent on channel_info members ordering

Purpose of this test is to avoid failing tests due to list ordering not
being always predictable in channel_info.

Some out of office tests are dependent on channel_info ordering. Indeed one
test relies on members list ordering (using [0] and [1]) instead of fetching
the right member in the given result list. In this commit we

  * ensure members in channel_info effectively match expected members;
  * check content of the right channel info member instead of relying on
    list order;

LINKS

Task ID-2070632 (main task)
Task ID-2419762 (followup task)
COM PR odoo/odoo#62859
ENT PR odoo/enterprise#15172
UPG PR odoo/upgrade#2005

addons/hr_holidays/tests/test_out_of_office.py

@@ -52,8 +52,11 @@ class TestOutOfOffice(TestHrHolidaysCommon):
             'name': 'test'
         })
         channel_info = channel.channel_info()[0]
-        self.assertFalse(channel_info['members'][0]['out_of_office_date_end'], "current user should not be out of office")
-        self.assertEqual(channel_info['members'][1]['out_of_office_date_end'], leave_date_end, "correspondent should be out of office")
+        self.assertEqual(len(channel_info['members']), 2, "Channel info should get info for the 2 members")
+        partner_info = next(c for c in channel_info['members'] if c['email'] == partner.email)
+        partner2_info = next(c for c in channel_info['members'] if c['email'] == partner2.email)
+        self.assertFalse(partner2_info['out_of_office_date_end'], "current user should not be out of office")
+        self.assertEqual(partner_info['out_of_office_date_end'], leave_date_end, "correspondent should be out of office")
 
 
 @tagged('out_of_office')