tests: {successorssets} now always return a list, affecting json output
CORE-TEST-OUTPUT-UPDATE: f95b23283760
This instance will be updated to Heptapod 18.6.0rc1 on 2025-12-08 between 11:00 and 12:00 UTC+1 (Europe/Paris)
CORE-TEST-OUTPUT-UPDATE: f95b23283760