Investigate if we still need `aws-serverless-lambda-layer-fix` plugin

[msonnb]

We currently transform all new ImportInTheMiddle() constructors to new ImportInTheMiddle.default(). Investigate whether we still need this. ref #12009 (comment)

[github-actions]

A PR closing this issue has just been released 🚀

This issue was referenced by PR #17012, which was included in the 10.0.0 release.