Steps to reproduce the issue

1. some table in a component: class XxxTable extends Table
2. without defination "protected $_supportNullValue = true;"
3. standard MVC in backend
4. edit the record A from that table and close it properly.

Expected result

1. Joomla\CMS\Table\Table checkIn gets processed
2. Record A should not be locked for other backend users
3. The record A should not be counted as checked_out item in Joomla -> Maintanence -> Global Check-in by the table Xxx.

Actual result

1. Joomla\CMS\Table\Table checkIn got processed -> correct
2. Record A was not locked for other backend users -> correct
3. The record A was still counted as checked_out item in Joomla -> Maintanence -> Global Check-in by table Xxx.

System information (as much as possible)

Joomla! 4.3.3 Stable Release Version

Additional comments

Joomla\CMS\Table\Table function checkIn():
If the table is not defined with "_supportNullValue=true", checked_out and checked_out_time will be set to 0 as well as sql nulldate instead of "NULL" and "NULL".
Shouldn't they (0, sql nulldate by checked_out, checked_out_time) also be excluded from the checked_out items?