[Sha 256] Project wiki repos should have the same repository object format as project
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When a user creates a project using the experimental SHA256 object format, they may expect that when wikis are created in that project, that they too would default to using the same object format.
See https://gitlab.com/gitlab-org/gitlab/-/issues/463827+ for similar issue with snippets
## Where in the application are you seeing this issue?
### URL of the page
- http://gdk.test:3000/root/sha256-snippet/-/wikis
### How did you expect the application to behave?
- Expected that the wiki repository would have the same object format as the 'parent' project
### How did the application behave?
- no observable errors
<!-- Provide a description of how the application actually behaved -->
issue