fix "deletion already in-progress" bug

[CollinBeczak]

Issue originally discussed in slack #maproulette-dev channel: https://osmus.slack.com/archives/C04M1NHPEQY/p1730405450254649

Issue: Challenges are unable to be edited in many ways whenever a task is in the process of deleting tasks. There is an edge case scenario, that this pr fix's, were the "deleting tasks" status on a challenge persists indefinitely.

Steps to reproduce bug bug:

1. Create a challenge with no tasks ( results in a challenge with no status ).
2. Delete tasks in the challenge via the deleteTasks endpoint using the api.
3. Try again and see error.

This is fixed by preventing the challenge status resetting after all tasks are deleted if there was no original status.

[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarCloud

[ljdelight]

Steps to reproduce bug bug:

1. Create a challenge with no tasks ( results in a challenge with no status ).
2. Delete tasks in the challenge via the deleteTasks endpoint using the api.

In step 2, what does it mean to delete tasks from the challenge (which was created with no tasks)? The challenge doesn't have any tasks, and I'm not sure what step 2 is meant to accomplish.