Reproduction link or steps

Try migrating any of the https://github.com/netlify/primitives/ packages.

1. Clone repo
2. go to e.g. packages/types
3. npx tsdown migrate
4. ENTER
5. check new config

What is expected?

The bundle option is not in the config (as it doesn't exist in tsdown), but depending on the value, either nothing happens (bundle: true) or unbundled more is set (I assume) when bundle: false

What is actually happening?

The option is still there.

Any additional comments?

No response