Reintroduce recursive_approach_for_all_projects default-enabled

What does this MR do?

Reintroduced the recursive_approach_for_all_projects feature flag which was removed in !55043 (merged). It also default-enables the FF so as not to disrupt GitLab.com or self-managed instances that are not experiencing problems.

However, this gives customers that are experiencing performance problems after upgrading a temporary path to unblock. Then we can address the performance problems iteratively.

Related to #334251 (closed).

Screenshots (strongly suggested)

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

Does this MR contain changes to processing or storing of credentials or tokens, authorization and authentication methods or other items described in the security review guidelines? If not, then delete this Security section.

  • Label as security and @ mention @gitlab-com/gl-security/appsec
  • The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
  • Security reports checked/validated by a reviewer from the AppSec team
Edited by Drew Blessing