Optimize Chunk.iterate

[adamgfraser]

No description provided.

[adamgfraser]

MIMA was reporting binary compatibility issues on Scala 2.12 and 2.13:

[error]  * static method iterate(java.lang.Object,Int,scala.Function1)scala.collection.GenTraversable in class zio.Chunk has a different result type in current version, where it is zio.Chunk rather than scala.collection.GenTraversable

[error]  * static method iterate(java.lang.Object,Int,scala.Function1)java.lang.Object in class zio.Chunk has a different result type in current version, where it is zio.Chunk rather than java.lang.Object

However, I think these are false positives because the Chunk companion object extends IndexedSeqFactory[Chunk] and StrictOptimizedSeqFactory[Chunk] on Scala 2.12 and 2.13 which already guarantees that the output type is a Chunk and Chunk is a subtype of both GenTraversable and Object. I believe related to lightbend-labs/mima#388.