build: use pnpm to note that ng-dev is a script in update-generated-files script (#2955)

PR Close #2955

Author: josephperrott

package.json

@@ -13,7 +13,7 @@
     "ng-dev": "bash ./tools/local-dev.sh",
     "lint": "tslint -c tslint.json --project tsconfig.json",
     "build-env-stamp": "tsx --tsconfig tsconfig.json ./ng-dev/release/stamping/_private_main.ts build-env-stamp",
-    "update-generated-files": "ng-dev misc update-generated-files"
+    "update-generated-files": "pnpm ng-dev misc update-generated-files"
   },
   "exports": {
     "./*": {