remove modularization helper scripts (tensorflow#4612)

INTERNAL

Author: tafsiri

tfjs-backend-webgl/package.json

@@ -44,7 +44,6 @@
     "tslint": "~5.11.0",
     "tslint-no-circular-imports": "~0.5.0",
     "typescript": "3.5.3",
-    "ts-morph": "^8.1.2",
     "yalc": "~1.0.0-pre.21"
   },
   "scripts": {