remove NodeJsFunction constructs from library

If we ever want to move this library into aws-cdk-lib, we cannot depend on experimental constructs. We will have to figure out a different way to bundle assets and refactor the two custom resource lambdas that currently utilize `NodeJsFunction`.

The issue identifies two custom resource lambdas that currently use NodeJsFunction, but it names no files or tests. Start by locating those lambdas and tracing how their assets are bundled; done means the library no longer depends on the experimental construct and both lambdas still bundle correctly for AWS CDK compatibility.

Written by the indexing model from the issue text.