Ominous item spawners are unaffected by the `Silent` NBT tag

When summoning an ominous_item_spawner with Silent set to true, all the corresponding sound effects still play.

Steps to Reproduce:

1. Summon a Silent ominous_item_spawner:

   summon ominous_item_spawner ~ ~ ~ {spawn_item_after_ticks:40,item:{id:"snowball",count:1},Silent:true}

2. Hear the sound still playing.