Adjust plugin dependencies

[noherczeg]

This is a question / suggestion.

Currently the dep graph looks like this:

"dependencies": {
    "less": "*",
    "sass": "*",
    "stylus": "*",
    "vite": "2.6.14"
  }

• less, sass, and stylus are not used, should be removed.
• vite is only used for types, therefore should be at most a peerDependency, ot maybe just a devDependency.