Cleans up the bypass_registration experiment

What does this MR do and why?

Resolves #350278 (closed)

This removes the control experience from the bypass_registration experiment and implements the feature as defined in the candidate definition since it was considered successful.

1. Register a new account
2. In the subsequent step, indicate that you're joining a project instead of creating one
3. Upon submission (depending on other feature flags and experiments) you're taken to your dashboard instead of down the process of creating a project

There are a few feature flags and experiments being run in the same area, so you may have a different experience based on other feature flags or experiments you may have set in other MR verification steps. This experiment is ~6 months old, but is described in some detail on the original experiment issue.

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.