scheduler v2.3.0: AttributeError: 'dict' object has no attribute 'type'

Sentry Issue: SWH-SCHEDULER-CK

AttributeError: 'dict' object has no attribute 'type'
  File "/opt/swh/.local/lib/python3.10/site-packages/swh/scheduler/cli/admin.py", line 83, in runner
    ntasks = len(run_ready_tasks(scheduler, app, task_types, with_priority))
  File "/opt/swh/.local/lib/python3.10/site-packages/swh/scheduler/celery_backend/runner.py", line 81, in run_ready_tasks
    task_type_name = task_type.type

Other related issues with the v2.3.0 [1] [2]

[1] https://sentry.softwareheritage.org/organizations/swh/issues/110575/?_allp=1&query=is%3Aunresolved&referrer=issue-stream&stream_index=1

[2] https://sentry.softwareheritage.org/organizations/swh/issues/110578/?project=7&query=is%3Aunresolved&referrer=issue-stream&stream_index=1