[m-rev.] diff: Delete unused imports.

[Peter Wang]

On Wed, 30 Mar 2022 12:41:29 +1100 "Zoltan Somogyi" <zoltan.somogyi at runbox.com> wrote:
> 
> One question I forgot earlier: does this change warrant an entry in NEWS?
> I think it is on the borderline.

You could add something brief like:

* We have fixed a bug where --warn-unused-imports did not warn about
  unused modules that are also imported by an ancestor of the current
  module.

Peter