Replace public_jobs attribute with public_builds attribute in Projects API docs

What does this MR do?

The Projects API takes the public_builds attribute rather than the public_jobs attribute. The attribute public_builds is defined in the api code base, while public_jobs is not. If you try to pass public_jobs when updating or creating a project, you'll get an error:

{"error":"jobs_enabled, resolve_outdated_diff_discussions, ci_config_path, container_registry_enabled, default_branch, description, issues_enabled, lfs_enabled, merge_requests_enabled, merge_method, name, only_allow_merge_if_all_discussions_are_resolved, only_allow_merge_if_pipeline_succeeds, path, printing_merge_request_link_enabled, public_builds, request_access_enabled, shared_runners_enabled, snippets_enabled, tag_list, visibility, wiki_enabled, avatar, approvals_before_merge, repository_storage, external_authorization_classification_label, import_url are missing, at least one parameter must be provided"}

While passing public_builds does not give this error. In the API response for projects, this attribute is labeled public_jobs.

What are the relevant issue numbers?

No issue, customer is requesting in ticket https://gitlab.zendesk.com/agent/tickets/108555 (internal use only)

Does this MR meet the acceptance criteria?

• Changelog entry added, if necessary
• Documentation created/updated
• Tests added for this feature/bug
• Conforms to the code review guidelines
• Conforms to the merge request performance guidelines
• Conforms to the style guides
• Conforms to the database guides
• Link to e2e tests MR added if this MR has Requires e2e tests label. See the Test Planning Process.