Move some project routes under /-/ scope

Signed-off-by: Dmitriy Zaporozhets <dmitriy.zaporozhets@gmail.com>

changelogs/unreleased/dz-scope-project-routes.yml

+---
+title: Move some project routes under /-/ scope
+merge_request: 28435
+author:
+type: changed

config/routes/repository.rb

@@ -39,7 +39,7 @@ scope format: false do
     end
   end
 
-  scope constraints: { id: Gitlab::PathRegex.git_reference_regex } do
+  scope path: '-', constraints: { id: Gitlab::PathRegex.git_reference_regex } do
     resources :network, only: [:show]
 
     resources :graphs, only: [:show] do