Bug: Schedule dialog doesn't have "Move to backlog" option

[bytrangle]

May be related to #3874

Your Environment

• Version used:11.1.2
• Operating System and version: Linux Mint
• Desktop Environment:
• Browser Name and version:

Expected Behavior

For tasks belonging to a project whose settings include "Enable Project Backlog", the schedule dialog should have "Move task to backlog until scheduled" checkbox.

Current Behavior

Currently, it doesn't.

Steps to Reproduce (for bugs)

1. Make sure that the target project has "Enable Project Backlog" toggled on in the settings
2. Add a task and assign it to the given project.
3. Right click the task and select "Schedule"
4. The schedule dialog should include a "Move to Backlog" checkbox.

As can be seen, task 2 is assigned to project "Project 1", which has "Enable Project Backlog" enabled. However, when scheduling this task, there is no option for moving it to backlog.
I think having the option to move a task to the backlog is a great way to keep the app clutter-free.

Can you reproduce this reliably?

Yes

Console Output

Error Log (Desktop only)

[github-actions]

Thank you very much for opening up this issue! I am currently a bit overwhelmed by the many requests that arrive each week, so please forgive me, if I fail to respond personally. I am still very likely to at least skim read your request and I'll probably try to fix all (real) bugs if possible and I will likely review every single PR being made (please, give me a heads up if you intent to do so) and I will try to work on popular requests (please upvote via thumbs up on the original issue) whenever possible, but trying to respond to every single issue over the last years has been kind of draining and I need to adjust my approach for this project to remain fun for me and to make any progress with actually coding new stuff. Thanks for your understanding!