Don't redundantly run ATTW

[lishaduck]

Clear and concise description of the problem

When creating n bundles, attw gets run over all of them n times.

Suggested solution

Synchronize them so tsdown does less work?

Alternative

Run it once per output

Additional context

Could be seen as a bug?

Validations

• Follow our Code of Conduct
• Read the Contributing Guide.
• Check that there isn't already an issue that request the same feature to avoid creating a duplicate.

[sxzz]

Sorry for wrong issue number