Change urgency of API project/:id/share to `low`

This endpoint does not meet the default latency target of 1 second in
some scenarios. So changing the urgency to `low` instead. 5 second
target should be tolerable for this endpoint.

lib/api/projects.rb

@@ -768,7 +768,7 @@ def add_import_params(params)
         requires :group_access, type: Integer, values: Gitlab::Access.all_values, as: :link_group_access, desc: 'The group access level'
         optional :expires_at, type: Date, desc: 'Share expiration date'
       end
-      post ":id/share", feature_category: :groups_and_projects do
+      post ":id/share", feature_category: :groups_and_projects, urgency: :low do
         authorize! :admin_project, user_project
         shared_with_group = Group.find_by_id(params[:group_id])