rename Kurs; Remove invalid activity_responsible

[pmattmann]

Fix Dev-Data:

• Rename Motto von Kurs (damit anders als 'Sola 2023')
• Remove invalid ActivityResponsible (Activity.Camp != CampCollaboration.Camp)
  resolves Error during rendering of program in print #6037

[BacLuc]

thank you

Please do this with a new data migration version, else you have to fix it manually on dev.
(and all devs need to delete their db to get your change)
https://github.com/ecamp/ecamp3/blob/de7e35dfe0cb4a0d8230ce246766661072b29cb9/api/migrations/dev-data/README.md

[pmattmann]

Please do this with a new data migration version, else you have to fix it manually on dev. (and all devs need to delete their db to get your change) https://github.com/ecamp/ecamp3/blob/de7e35dfe0cb4a0d8230ce246766661072b29cb9/api/migrations/dev-data/README.md

Done