Fixed the custom roles not listing issue

[ABHISHEK2k6]

No description provided.

[greptile-apps]

Greptile Summary

This PR updates campus role listing and adds automatic alumni-status synchronization. The main changes are:

• Includes custom executive roles while filtering generated IG campus-lead titles.
• Adds an idempotent Celery task to update alumni status from graduation years.
• Registers the new alumni task with the Celery application.

Confidence Score: 5/5

No additional blocking issue qualifies for this follow-up review.

• No distinct production failure remains to report within the required follow-up scope.
• The alumni task uses repeatable bulk updates and is explicitly loaded by Celery.

Important Files Changed

Filename	Overview
api/dashboard/campus/events_views.py	Updates the campus executive-role list to include custom roles and exclude generated IG campus-lead titles.
mu_celery/alumni_cron.py	Adds bulk updates that synchronize college alumni status using valid four-digit graduation years.
mulearnbackend/celery.py	Explicitly registers the new alumni cron module when Celery starts.

_{Reviews (3): Last reviewed commit: "Fixed the roles not listing issue + alum..." | Re-trigger Greptile}