refactor(turnstile): Remove turnstile (#11387)

This PR removes turnstile from the platform.

#### For code changes:
- [x] I have clearly listed my changes in the PR description
- [x] I have made a test plan
- [x] I have tested my changes according to the test plan:
  <!-- Put your test plan here: -->
  - [x] Test to make sure that turnstile is gone, it will be.
  - [x] Test logging in with out turnstile to make sure it still works
  - [x] Test registering a new account with out turnstile and it works

autogpt_platform/frontend/package.json

@@ -30,7 +30,6 @@
   "dependencies": {
     "@faker-js/faker": "10.0.0",
     "@hookform/resolvers": "5.2.2",
-    "@marsidev/react-turnstile": "1.3.1",
     "@next/third-parties": "15.4.6",
     "@phosphor-icons/react": "2.1.10",
     "@radix-ui/react-alert-dialog": "1.1.15",