Bump knockout from 3.4.0 to 3.5.0 in /samples/knockout-sp-pnp-js

Bumps [knockout](https://github.com/knockout/knockout) from 3.4.0 to 3.5.0.
- [Release notes](https://github.com/knockout/knockout/releases)
- [Commits](https://github.com/knockout/knockout/compare/v3.4.0...v3.5.0)

Signed-off-by: dependabot[bot] <support@github.com>

samples/knockout-sp-pnp-js/package-lock.json

@@ -10338,9 +10338,9 @@
       }
     },
     "knockout": {
-      "version": "3.4.0",
-      "resolved": "http://registry.npmjs.org/knockout/-/knockout-3.4.0.tgz",
-      "integrity": "sha1-WdcmGBWhHrfBo/PHB3yomKRMqts="
+      "version": "3.5.0",
+      "resolved": "http://registry.npmjs.org/knockout/-/knockout-3.5.0.tgz",
+      "integrity": "sha512-vBUF/IsBDzaejHkNpiquKdc5uPrImXuQ4Mb9lEfNNJ5cyHGI8ThDupR+h3eMFZhfmPE/brfwcIAn/fm0yOvJUg=="
     },
     "lazy-cache": {
       "version": "1.0.4",

samples/knockout-sp-pnp-js/package.json

@@ -22,7 +22,7 @@
     "@types/es6-promise": "0.0.33",
     "@types/knockout": "3.4.39",
     "@types/webpack-env": "1.13.1",
-    "knockout": "3.4.0"
+    "knockout": "3.5.0"
   },
   "devDependencies": {
     "@microsoft/sp-build-web": "1.7.0",