Update Product Artists

curl --request PUT \
  --url https://server26-dot-royalti-project.uc.r.appspot.com/product/{id}/artists \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '{
  "artists": [
    "artist-id-1",
    "artist-id-2"
  ]
}'

{
  "message": "Artist added to product"
}