build(docs-infra): upgrade `firebase-tools` to v8.14.1 (#39470)

This commit upgrades `firebase-tools` (used to deploy angular.io to
Firebase hosting) to the latest version. This gives us access to the
latest fixes/improvements and also new features, such as
[version cloning][1].

[1]:
https://firebase.google.com/docs/hosting/manage-hosting-resources#cli-commands-cloning

PR Close #39470

aio/package.json

@@ -128,7 +128,7 @@
     "eslint": "^3.19.0",
     "eslint-plugin-jasmine": "^2.2.0",
     "find-free-port": "^2.0.0",
-    "firebase-tools": "^7.11.0",
+    "firebase-tools": "^8.14.1",
     "fs-extra": "^2.1.2",
     "globby": "^6.1.0",
     "hast-util-is-element": "^1.0.0",