Improve Actions workflow that sends notification about issue comment to send Slack notification when bot comment was skipped #31

Summary

Adjust .github/workflows/contributor-issue-comment.yml workflow to send a notification to #support-dev-notifications Slack channel when a bot response was intentionally skipped on an issue due to the optimization that ensures that no more than one bot reply is sent per an hour. The text of the notification should be: "[repo] Bot response skipped on issue: Test issue (less than 1 hour since last bot reply)"

A follow-up to #29 (comment).

... I realized that for team members who are not familiar with the 1 hour optimization, not sending a bot reply and Slack notification about it may look like an error, despite it being intentional.

If we're skipping GitHub bot reply because it has been already sent in the past hour, could we send Slack notification about it too, that would include a brief note about why it's being skipped?

So for this situation, on Slack we would see:

[repo] New comment on issue: Test issue by MisRob2
[repo] Bot response skipped on issue: Test issue (less than 1 hour since last bot reply)

Additional benefit is that I will too see that everything is working as expected, and will be able to recognize this scenario easily from when there is an unexpected problem with the action.