Adding a new parent work type label will not remove the other child's work type label
Context
We noticed some inconsistencies in work type labels in #997 (closed).
The problem
- Data: bugavailability and typebug are present, and I add typefeature
- Expected labels: typefeature
- Actual labels: typefeature bugavailability
The child labels of another work type are not removed when adding a new parent work type.