Attribution set as part of `TileSet` not shown

[louwers]

To reproduce:

val osmTileSet = TileSet("osm", "https://tile.openstreetmap.org/{z}/{x}/{y}.png")
osmTileSet.attribution = "OSM Contributors"
val source = RasterSource("osm", osmTileSet, 128)
val layer = RasterLayer("osm-layer", "osm")

maplibreMap.setStyle(Style.Builder().withSource(source).withLayer(layer))

No attribution is shown.