Make sure scheduler threads don't ACK the quiescence protocol CNF messages if they have an actor waiting to be run

[dipinhora]

Make sure scheduler threads don't ACK the quiescence protocol CNF messages if they have an actor waiting to be run.

Resolves #4582

[SeanTAllen]

whenever this is "done, can you add comments explaining the various bit that this is testing?

i think it will be non-obvious to many folks even if I understand.

[dipinhora]

done

[SeanTAllen]

from the comment, perhaps we should call this regression-4582 ?

we have a number of full program tests with that naming scheme, named after the regression they are testing against.

[dipinhora]

done

[ponylang-main]

Hi @dipinhora,

The changelog - fixed label was added to this pull request; all PRs with a changelog label need to have release notes included as part of the PR. If you haven't added release notes already, please do.

Release notes are added by creating a uniquely named file in the .release-notes directory. We suggest you call the file 4583.md to match the number of this pull request.

The basic format of the release notes (using markdown) should be:

## Title

End user description of changes, why it's important,
problems it solves etc.

If a breaking change, make sure to include 1 or more
examples what code would look like prior to this change
and how to update it to work after this change.

Thanks.