fix(web): missing tslib dependency

Author: TorstenDittmann

templates/web/package.json.twig

@@ -28,6 +28,7 @@
     "playwright": "^1.10.0",
     "rollup": "^2.43.0",
     "serve-handler": "^6.1.3",
+    "tslib": "^2.2.0",
     "typescript": "^4.2.3"
   },
   "dependencies": {