deno add creates duplicate dependencies in package.json

[DanieliusDev]

Version: Deno 2.0.0

Reproduction

deno add npm:express
deno add -D npm:express

expected package.json:

{
  "devDependencies": {
    "express": "^4.21.1"
  }
}

actual package.json:

{
  "dependencies": {
    "express": "^4.21.1"
  },
  "devDependencies": {
    "express": "^4.21.1"
  }
}