fix test data: use correct provider key in setup test

Task 9 resolved (removed stale docs).
Provider key 'attack-on-titan' replaced with 'test-unknown-anime-2020'.

Docs/tasks.md

@@ -1,18 +1,3 @@
-## Task 9: API Scheduler - Empty Schedule Days
-
-**Suite:** `Robot.Api.Scheduler`  
-**Test:** `Empty Schedule Days`  
-**Result:** FAIL  
-**Error:** `Url: http://127.0.0.1:8765/api/scheduler/config Expected status: 422 != 200`
-
-**Instructions:**
-- Investigate the `PUT /api/scheduler/config` endpoint when `schedule_days` is an empty list/array.
-- The test expects the backend to accept empty schedule days (HTTP 200), but it returns 422.
-- Check the Pydantic validator for `schedule_days` — it may require at least one day.
-- Decide whether empty schedule days should be allowed (update backend) or rejected (update test to expect 422).
-
----
-
 ## Task 10: API Setup - Resolve Folder With Provider Key
 
 **Suite:** `Robot.Api.Setup`