The filterMode Doesn't Update from includeAll to excludeAll

[zackcl]

Version where bug was found:
6.1.0

Describe the bug
When an experiment has no participants, the "filterMode" should be set to "excludeAll". This works as expected when an experiment is created without participants. However, once the "filterMode" is set to "includeAll" (by adding an "All" row to the Include table), it doesn't revert back to "excludeAll" after removing the "All" row from the Include table. I believe this issue should be addressed as a hotfix for v6.0 since it's crucial.

To Reproduce
Steps to reproduce the behavior:

1. Create an experiment with no participants
2. Open the "Network" tab in the browser inspector to see the response from the /api/experiments/single/{experimentId} endpoint
3. Observe that the "filterMode" is set to "excludeAll" (expected behavior)
4. Update the experiment by adding an "All" row to the Include table
5. View the response from the /api/experiments/single/{experimentId} endpoint again
6. Observe that the "filterMode" is set to "includeAll" (expected behavior)
7. Update the experiment by removing the "All" row from the Include table
8. View the response from the /api/experiments/single/{experimentId} endpoint again
9. Observe that the "filterMode" remains set to "includeAll" when it should have updated to "excludeAll"
10. Verify by making /api/v5/init and /api/v5/assign requests with any user ID to confirm that users are not being excluded

Expected behavior
The experiment's "filterMode" should update from "includeAll" to "excludeAll" when the "All" row is removed from the Include table.

Screen recording

filterMode.bug.720p.mov

[zackcl]

I will investigate if there are any other experiments like "LiveHint AI - Tutorbot for MATHstream" that have no participants but have their "filterMode" set to "includeAll" on Prod UpGrade so that we can update them if needed.

[zackcl]

I've verified that the filterMode settings for all experiments on Production are correctly set.