DEPRECATION NOTICE: cjs export & Task operators

[realpha]

In the upcoming major release, support for cjs modules will be dropped. I don't see much value in the dual export as it stands today. It unnecessarily doubles the package size and esm is THE standard.
If anybody really needs it, I might provide a dedicated NPM package for it, otherwise it's gone for good.

Additionally I will remove the the Task operators for now as well. Without a pipe API this doesn't make too much sense and the ergonomics of a fluent API are far superior in my opinion.