Currently the "ngtsc` testing helpers resolve the `fake_core` NPM
package using the `TEST_SRCDIR` variable. This is problematic on Windows
where Bazel runfiles are not symlinked into the runfiles directory.
In order to properly resolve the NPM Bazel tree artifact, we use the
`resolveTreeNpmArtifact` runfile helper that properly resolves the artifact
properly on all platforms.
PR Close#28352