No warning when the manually specified table doesn't actually annotate the labels element

<img width="686" alt="Image" src="https://github.com/user-attachments/assets/1c919b08-cc52-4eb2-85d7-4bcafc00763e" />

I forgot to set the spatialdata_attrs so the function was generating random colors for my labels - instead it should've failed and told me that the table doesn't annotate that labels object.