Remove preloading of forks in projects API

We don't need to load all the forks to generate the forks_count because
we do a separate query to do this efficiently

Changelog: performance
MR: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/62602

lib/api/entities/project.rb

@@ -136,7 +136,7 @@ module API
                                 .preload(project_group_links: { group: :route },
                                          fork_network: :root_project,
                                          fork_network_member: :forked_from_project,
-                                         forked_from_project: [:route, :forks, :tags, :group, :project_feature, namespace: [:route, :owner]])
+                                         forked_from_project: [:route, :tags, :group, :project_feature, namespace: [:route, :owner]])
       end
       # rubocop: enable CodeReuse/ActiveRecord