Prevent stale data in LDAP group sync last owner check

CHANGELOG-EE

@@ -3,6 +3,9 @@ Please view this file on the master branch, on stable branches it's out of date.
 v 8.10.0 (unreleased)
   - Rename Git Hooks to Push Rules
 
+v 8.9.5
+  - Prevent stale data in LDAP group sync last owner check.
+
 v 8.9.4
   - Improve how File Lock feature works with nested items. !497
 

lib/gitlab/ldap/group_sync.rb

@@ -304,6 +304,11 @@ module Gitlab
             next
           end
 
+          # Since we're removing users in this loop, `group.reload`
+          # before checking `last_owner?` to prevent stale owner information.
+          # Without a reload, this check would return a false negative.
+          group.reload
+
           # Check and update the access level. If `desired_access` is `nil`
           # we need to delete the user from the group.
           if desired_access.present?