Fix to new badge being shown on channel delete

[thesujai]

Summary

The cause of the bug is well addressed in #6730 (comment)

For handling that we will show new badge based on the latest task which will be the task with highest scheduled_datetime(among the tasks with same channel_id)
Screencast
Here I delete resource initially(shows no new badge)
Then install more resource(shows new badge as it should)
Then remove a resource(shows no new badge, as it shouldn't)
Screencast from 28-12-23 04:11:18 PM IST.webm

…

References

Fixes #6730
…

Reviewer guidance

…

---

Testing checklist

• Contributor has fully tested the PR manually
• If there are any front-end changes, before/after screenshots are included
• Critical user journeys are covered by Gherkin stories
• Critical and brittle code paths are covered by unit tests

PR process

• PR has the correct target branch and milestone
• PR has 'needs review' or 'work-in-progress' label
• If PR is ready for review, a reviewer has been added. (Don't use 'Assignees')
• If this is an important user-facing change, PR or related issue has a 'changelog' label
• If this includes an internal dependency change, a link to the diff is provided

Reviewer checklist

• Automated test coverage is satisfactory
• PR is fully functional
• PR has been tested for accessibility regressions
• External dependency files were updated if necessary (yarn and pip)
• Documentation is updated
• Contributor is in AUTHORS.md

[github-actions]

Build Artifacts

Asset type	Download link
PEX file	kolibri-0.16.0b10.dev0_git.55.g256f9054.pex
Windows Installer (EXE)	kolibri-0.16.0b10.dev0+git.55.g256f9054-unsigned.exe
Debian Package	kolibri_0.16.0b10.dev0+git.55.g256f9054-0ubuntu1_all.deb
Mac Installer (DMG)	kolibri-0.16.0b10.dev0+git.55.g256f9054-0.3.0.dmg
Android Package (APK)	kolibri-0.16.0b10.dev0+git.55.g256f9054-0.1.0-debug.apk
TAR file	kolibri-0.16.0b10.dev0+git.55.g256f9054.tar.gz
WHL file	kolibri-0.16.0b10.dev0+git.55.g256f9054-py2.py3-none-any.whl

[rtibbles]

Code changes look fine - @pcenov could you verify the fix? It seems that the key to replication is to have imported some resources, and then to have deleted a resource without having cleared the import task.

[rtibbles]

@thesujai this is great, could you retarget to release-v0.16.x and rebase to that branch too? We can release this in a patch release to 0.16.

[thesujai]

Hey @rtibbles 👋🏽
🚀 Changes are now targeted for release-v0.16.x and rebased onto it. Ready to roll for a patch release to 0.16!
Check it out and let me know if tweaks are needed.

[pcenov]

@rtibbles I confirm that this is implemented as specified, passes manual QA. Thank you @thesujai!

[rtibbles]

Thanks @thesujai - looks like this is ready to go. We'll hold off merging until 0.16.0 has been released, but no more work needs to be done here!

[rtibbles]

Actually, we changed our minds, and this is safe enough to merge for 0.16.0, thank you for your contribution!