Updates the custom data for a quest

curl --request PATCH \
  --url https://api.drip.re/api/v4/quests/realms/{id}/quests/{quest_id}/custom \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "custom_data": {}
}'

{
  "message": "Ok"
}