Enable Arkose Labs Challenge for Trial Signups

What does this MR do and why?

This MR adds the Arkose Labs Challenge for the Trial Signup flow.

Issue: https://gitlab.com/gitlab-org/modelops/anti-abuse/team-tasks/-/issues/230+

Screenshots or screen recordings

Trial Signup - Arkose disabled	Trial Signup - Arkose enabled
Screen_Recording_2023-03-09_at_16.58.36	Screen_Recording_2023-03-09_at_17.02.58

How to set up and validate locally

1. Enable Arkose Labs on signup (the Arkose Labs public and private API keys can be found in the 1Password Engineering Vault entry named ArkoseLabs API keys > GITLAB - DEVELOPMENT - REGISTRATION FLOW). Optionally enable Identity Verification.

   Feature.enable(:arkose_labs_signup_challenge)
   Feature.enable(:arkose_labs_trial_signup_challenge)
   Feature.enable(:identity_verification) # optional
   Feature.disable(:soft_email_confirmation) # optional
   ApplicationSetting.current.update(arkose_labs_public_api_key: ***, arkose_labs_private_api_key: ***, arkose_labs_namespace: 'client')
   ApplicationSetting.current.update(email_confirmation_setting: 2) # optional
   ApplicationSetting.current.update(require_admin_approval_after_user_signup: false) # optional

2. Force ArkoseLabs to always require the user to solve the challenge. Update ee/app/assets/javascripts/arkose_labs/components/sign_up_arkose_app.vue, line 63:

   arkoseObject.setConfig({
   + data: { id: 'ML_defence' }, // ADD THIS LINE
     mode: 'inline',
     selector: `.${this.arkoseContainerClass}`,
     onShown: this.onArkoseLabsIframeShown,
     onCompleted: this.passArkoseLabsChallenge,
   });

3. Enable reCAPTCHA on signup to verify the default behavior

4. Start GDK with GITLAB_SIMULATE_SAAS=1 to simulate SaaS

5. Visit http://localhost:3000/-/trial_registrations/new and signup

MR acceptance checklist

This checklist encourages us to confirm any changes have been analyzed to reduce risks in quality, performance, reliability, security, and maintainability.

• I have evaluated the MR acceptance checklist for this MR.