RFR: 2326: Don't send the ready for sponsor comment to mailing list if the pr is closed [v2]

[Zhao Song]

> After we deployed [SKARA-2302](https://bugs.openjdk.org/browse/SKARA-2302) and [SKARA-2322](https://bugs.openjdk.org/browse/SKARA-2322), some users complained about receiving numerous "ready for sponsor" emails from closed PRs.
> We should prevent the bot from retroactively sending out these emails.

Zhao Song has updated the pull request incrementally with one additional commit since the last revision:

  review comment

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Changes:
  - all: https://git.openjdk.org/skara/pull/1676/files
  - new: https://git.openjdk.org/skara/pull/1676/files/7cd0152d..7d8f4396

Webrevs:
 - full: https://webrevs.openjdk.org/?repo=skara&pr=1676&range=01
 - incr: https://webrevs.openjdk.org/?repo=skara&pr=1676&range=00-01

  Stats: 1 line in 1 file changed: 0 ins; 0 del; 1 mod
  Patch: https://git.openjdk.org/skara/pull/1676.diff
  Fetch: git fetch https://git.openjdk.org/skara.git pull/1676/head:pull/1676

PR: https://git.openjdk.org/skara/pull/1676