Create a sub-task should not keep it attached to the old parent task

[yairopro]

Steps to reproduce:

1. Create a task A
2. Create a task B
3. From A, open the modal to create a subtask C but do not submit.
4. Leave the modal by clicking on the backdrop (the intent is to cancel the creation)
5. From B, open the modal to create a subtask D and submit.

State:
The task D 's parent is A.

Expected state:
The task D 's parent should be B.

Screen.Recording.2026-01-02.at.14.05.30.mp4