Use create_wiki method on ensure_wiki_exists in update_service

Merged Thibault requested to merge Neinea/gitlab:master into master

What does this MR do?

Related to #241619 (closed). The scope of this merge request is to re-enable wiki after disable it.

Screenshots

Does this MR meet the acceptance criteria?

Conformity

Availability and Testing

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

  • [-] 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 Luke Duncalfe