gitlab: Fix bot-token-extender script not extending project membership

The project membership must also be extended, if not the user is simply
deleted when the membership expires (defeating the purpose of extending
the access tokens).

Fixes: 639101e6 ("gitlab: Add ruby script for continuous extending of bot tokens")

roles/gitlab/templates/gitlab-bot-token-extender.rb.j2

@@ -3,5 +3,6 @@ bots = [{{ gitlab_bots | map("to_json") | join(', ') }}]
 bots.each do |username|
   puts "Bot user: #{username}"
   user = User.find_by_username(username)
+  user.project_members.update_all(expires_at: 12.months.from_now)
   user.personal_access_tokens.update_all(expires_at: 12.months.from_now)
 end