Remove @types/node from dependencies

[ntkme]

Based on comments from #1736.

It seems to be common to use "@types/node": "*" when @types/node is required.

[Goodwine]

Interestingly when using a test package with:

  "dependencies": {
    "sass": "file:../<PATH_TO_DART_SASS>/build/npm"
  },

And then compiling import * as sass from 'sass' using NodeNext module/moduleResolution I get the same typing error regardless of whether the sass' package dependency 🤔

in other words it makes no difference whether the dependency is there or not.. perhaps it'd be better to remove it all together as suggested?
The reason I think is because @types/node exists within node_modules/sass/node_modules and TS requires the typings to exist under node_modules/<> or something like that 🤔

[ntkme]

@Goodwine I would prefer to remove it all together as well as it is more common for end users to install it themselves anyways.