This is needed to better support native ESM modules and avoid the otherwise necessary deep imports like `zone.js/fesm2015/zone-node.js` due to disallowed directory imports.
PR Close#51652
Since v15, prod mode is handled by the CLI with the `optimization` flag. We can remove the environement files and `enableProdMode` when the tests use the CLI.
PR Close#49746
This commit adds an integration test that uses `@angular/elements` with
`@angular/platform-server` in order to highlight a current
incompatibility. The issue will be fixed in a subsequent commit.
PR Close#40559
