[C2] "Last connexion" column empty in users list as admin

[ywarnier]

Describe
As an admin, when I look at the users list, the "Last connexion" column is empty.
The registration date is not empty, so all good on that side.
I logged in as the first user in the screenshot, and you can see the field is empty.

To Reproduce
Steps to reproduce the behavior:

1. Go to '/main/admin/user_list.php' as admin
2. See that the Last connexion column is empty for all users

Expected behavior
A date similar to the one in "Registration date" should show in the "Last connexion" column.

Screenshots

Desktop (please complete the following information):
Not important

**Server

• OS: Linux Ubuntu
• Version of Chamilo: 2.0 from git Monday
• Version of PHP: 8.3

Reported by @klineur-M