🐛 Bug: Transition mode duplicates some "templated by" notices

[JoshuaKGoldberg]

Bug Report Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have searched for related issues and found none that matched my issue.

Expected

Running npx create-typescript-app on an existing repo with a templated by notice shouldn't duplicate any part of it.

Actual

https://github.com/JoshuaKGoldberg/prune-github-notifications/pull/201/files#r2028679013 shows that it is.

Additional Info

Continuation of #2124.

🎁

[github-actions]

🎉 This is included in version v2.26.6 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀