Disable node_modules lookup for all subpaths of builtin modules

[targos]

Something else discussed in https://github.com/nodejs/node/pull/44250 that we should consider is making new subpath additions (like any other core module getting /promises) allowable as semver-minor. This might be a code change, to ensure that nonexistent subpaths (like process/promises) throw rather than try to resolve to something like node_modules/process/promises; but once that’s done we should update the docs accordingly.

Originally posted by @GeoffreyBooth in https://github.com/nodejs/node/issues/44576#issuecomment-1241239416