Cache node_modules directory

Is it possible for the cache to work on both `$DENO_DIR` and node_modules (optionally)? There are some cases where both directories are used (vite, playwright, etc)

It also appears there's a change in deno module handling where setting the `node_modules_dir=auto` option no longer stores jsr libraries in node_modules, so we have split directories by default

No file or test is named in the issue; start by tracing how the GitHub Action currently caches `$DENO_DIR` and how its cache inputs are configured. Check the Deno and node_modules behavior described for Vite and Playwright, and consider the issue done when both directories can be cached optionally without breaking the existing cache.

Written by the indexing model from the issue text.