Node Deprecation: Invalid main field in package.json for published package

This is happening with Angular and using the new Application Builder backed by `esbuild`.

```bash
(node:17001) [DEP0128] DeprecationWarning: Invalid 'main' field in '/home/circleci/project/repo/node_modules/@blackbaud/sky-addin-client/package.json' of 'dist/bundles/sky-addin-client.umd.js'. Please either fix that or report it to the module author
```