[tests] install root typescript version 4.9.5 and standardize on that version (#9858)

This add a root-level `typescript` version that matches the one used throughout for VS Code (and other IDEs) to use when browsing the code. After this PR merges, you will be able to set VS Code's TypeScript version to match the project's version.

This will remove issues where the IDE says TypeScript compilation is good to go, but `pnpm build` disagrees.

If there's a better way to allow this, please suggest it!

---

To enable:

<img width="849" alt="Screenshot 2023-04-25 at 4 28 22 PM" src="https://user-images.githubusercontent.com/41545/234408245-205b3260-7b1d-4c43-a531-d616915dbefb.png">

Then:

<img width="1015" alt="Screenshot 2023-04-25 at 4 29 20 PM" src="https://user-images.githubusercontent.com/41545/234408271-4e7b4ec8-0be3-4743-afd7-813a267c0756.png">

packages/python/package.json

@@ -25,7 +25,6 @@
     "@types/node": "14.18.33",
     "@vercel/build-utils": "6.7.1",
     "@vercel/ncc": "0.24.0",
-    "execa": "^1.0.0",
-    "typescript": "4.3.4"
+    "execa": "^1.0.0"
   }
 }