Remove unused add-changeset.js

Author: ninjasimon

package-lock.json

@@ -4,7 +4,6 @@
   "version": "4.0.0",
   "devDependencies": {
     "@changesets/cli": "^2.26.2",
-    "@changesets/write": "^0.2.3",
     "@rebilly/regenerator": "^0.0.10",
     "ts-node": "^10.9.2"
   },