chore: a more polite closed issue message

[kellertk]

Description of changes

The AWS SDKs received some customer feedback that our closed issue message is too loud and too full of emoji. This message is slightly more polite. If you disagree, please disregard this PR.

Issue #, if available

None

Description of how you validated changes

No testing was performed.

Checklist

• [X] PR description included
• [ ] yarn test passes
• [ ] Tests are changed or added
• [ ] Relevant documentation is changed or added (and PR referenced)
• [ ] New AWS SDK calls or CloudFormation actions have been added to relevant test and service IAM policies
• [ ] Pull request labels are added

By submitting this pull request, I confirm that my contribution is made under the terms of the Apache 2.0 license.