Use STM.foreach_ wherever possible

[mschuwalow]

Can only be resolved once we have upgraded ZIO version

[chlin501]

I am interested and would like to take this issue.

By the way, after cloning the repo (the latest revision is
eadb32f), I notice that in BuildHelper.scala zioVersion is "1.0.0-RC21-2", that contains STM. So I suppose this ticket doesn't need to upgrade zio to a newer version, right?

[mijicd]

@chlin501 No, we updated the zio version roughly a week ago. Now it's up to you to nuke foreach wherever applicable :).

[chlin501]

I created the PR [1]. It looks like only 2 files referenced to (Z)STM.foreach(). Please let me know if I miss any code that also references to (Z)STM.foreach(), or any issues in terms of this. I will update it again. Thanks!

[1]. #270

[mijicd]

Closed in #270