🐛 Bug: Don't create src/*.ts files during migration

[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

Migrating an existing repository (--mode migrate) generally doesn't need to create greet-related files (src/greet.ts, etc.). But that doesn't make much sense for a repository that likely already has code.

Actual

Right now, if you run --mode migrate in an existing repository that has src/index.ts, the file will get replaced with the default src/index.ts, src/greet.test.ts, etc.

Let's skip creating greet-related files during migration.

Additional Info

No response

[github-actions]

🎉 This is included in version v1.29.44 🎉

The release is available on:

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

Cheers! 📦🚀