build: remove unnecessary postinstall rules_nodejs patch

We recently updated to `rules_nodejs` 3.5.0. This contained a fix
for something we recently tried to achieve using a postinstall
patch. The PR that updated to 3.5.0 became a little out-of-date
due to the PR introducing the postinstall patch being merged, so
that the failure only surfaced when the update PR got merged.

Author: devversion