Remove node_modules when no node runtime is installed in the image ?

[Intrepidd]

In some cases (when grover is present for exemple) we need a node runtime to be able to launch some JS deps from ruby.

But, when no node runtime is installed, node_modules still lingers in the final image, which can consume a lot space.

I was wondering if this was on purpose, or if we could indeed remove the node_modules folder in this specific case ?

If so, I'm happy to write a PR for it if you give me some pointers on the preferred way to do it (just rm -r ? tweak the COPY statement ? )