Cannot stack multiple render commands of the same kind

[timtreis]

Based on: #190

MRE

import spatialdata as sd
from spatialdata.datasets import blobs
import spatialdata_plot

(
    blob
    .pl.render_shapes(elements="blobs_circles")
    .pl.render_shapes(elements="blobs_polygons")
    .pl.show()
)

Should have both shapes