Consider updating the dual module export system

The **Cloud SQL Node.js Connector** library was the first library from Cloud SDK to use a dual module export system, as such the conventions and [scripts](https://github.com/GoogleCloudPlatform/cloud-sql-nodejs-connector/blob/main/scripts/fixup.cjs) used here might not be in alignment with what the larger team will be using moving forward.

With that in mind, let's keep an eye and make sure to update the workflows on this library to make sure they align well with the tooling that the larger team is going to be using in the future.