CLI: Require main.js without cache in automigrations

[yannbf]

Closes #

What I did

Automigrations were failing sometimes because when the first automigration required main.js, it was put into cache, and the subsequent automigration would require a cached version of main.js, without the changes from previous automigrations, leading to errors like:

missing-babelrc:
Cannot read properties of undefined (reading 'name')

How to test

1. Bootstrap the libs
2. Go to a SB 6 project
3. Try to automigrate it
4. It should be successful. Before, it'd error with the message from above

Checklist

• Make sure your changes are tested (stories and/or unit, integration, or end-to-end tests)
• Make sure to add/update documentation regarding your changes
• If you are deprecating/removing a feature, make sure to update
  MIGRATION.MD

Maintainers

• If this PR should be tested against many or all sandboxes,
  make sure to add the ci:merged or ci:daily GH label to it.
• Make sure this PR contains one of the labels below.

["cleanup", "BREAKING CHANGE", "feature request", "bug", "documentation", "maintenance", "dependencies", "other"]

[shilman]

LGTM!! Great job @yannbf