[FIX] project: Fix sub-tasks stat button count
[FIX] project: Fix sub-tasks stat button count

Currently, In the project module, the archived/deleted sub-task is
not deducted from the count of the 'sub-tasks' stat button.

Steps to reproduce:
 - Go to Project > Configuration > Settings > Enable 'sub-tasks'
 - Go to a Project with sub-tasks enabled, open a task and create a sub-task
 - Archive/Delete this sub-task

So in this commit, we applied filter on sub-task which show only active
sub-task on the stat button.

closes odoo/odoo#55323

Taskid: 2304887
Closes: #54904
X-original-commit: 7fd3c7cdc8c3bbde73ea0ded5c97eb638a22d3f3
Signed-off-by: Yannick Tivisse (yti) <200a91eb0e5cc4726d6a3430713b580138f34298@odoo.com>

ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo,ygol/odoo