`Instant` are treated as unstable

[lydavid]

https://developer.android.com/develop/ui/compose/performance/stability/fix#modules-solution cause Instant comes from an external library without Compose compiler

When using layout inspector, the ThumbnailImage for each lookup history is set ablaze with blue, continuously recomposing. This was actually because of https://github.com/lydavid/MusicSearch/pull/990/files#diff-1c37605393d9de698bd9c0cb8ce1979525f40ef6f5f03201306c372a00fa1e0a

Ex

unstable class LookupHistoryListItemModel {
  stable val id: String
  stable val title: String
  stable val entity: MusicBrainzEntity
  stable val numberOfVisits: Int
  unstable val lastAccessed: Instant
  stable val imageUrl: String?
  <runtime stability> = Unstable
}

[lydavid]

Whether this is unstable or not does not affect recomposition counts, so we don't have to bother with this