chore: remove stage script from package.json

package.json

@@ -4,7 +4,6 @@
   "version": "1.0.0",
   "scripts": {
     "serve": "vue-cli-service serve",
-    "stage": "vue-cli-service build --mode staging",
     "build": "vue-cli-service build",
     "lint": "vue-cli-service lint",
     "changelog": "conventional-changelog -p angular -i CHANGELOG.md -s",