RFR: 1588: Bridge messages should not be sent for PRs in draft state

[Zhao Song]

On Thu, 9 Feb 2023 17:48:28 GMT, Guoxiong Li <gli at openjdk.org> wrote:

> Hi all,
> 
> This patch prevents the `mailling bridge bot` from sending emails when a PR is draft.
> And the related test case is added.
> 
> Thanks for taking the time to review.
> 
> Best Regards,
> -- Guoxiong

I think this patch could successfully help us postpone the sending of emails when the pr is in draft mode and some users will be happy to see this update.

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Marked as reviewed by zsong (Committer).

PR: https://git.openjdk.org/skara/pull/1469