Move callback into the correct model

update_staging_workflow_on_backend callback was moved into
staging_project model.

src/api/app/models/project.rb

@@ -28,9 +28,6 @@ class Project < ApplicationRecord
     @commit_opts = {}
   end
 
-  after_save :update_staging_workflow_on_backend
-  after_destroy :update_staging_workflow_on_backend
-
   has_many :relationships, dependent: :destroy, inverse_of: :project
   has_many :packages, inverse_of: :project do
     def autocomplete(search)
@@ -1747,13 +1744,6 @@ def has_local_distribution(project_name, repository)
         linked_repository.name == repository
     end
   end
-
-  def update_staging_workflow_on_backend
-    return unless staging_workflow_id
-
-    staging_workflow.reload
-    staging_workflow.write_to_backend
-  end
 end
 # rubocop:enable Metrics/ClassLength
 

src/api/app/models/staging/staging_project.rb

@@ -6,6 +6,9 @@ class StagingProject < Project
 
     default_scope { where.not(staging_workflow: nil) }
 
+    after_save :update_staging_workflow_on_backend
+    after_destroy :update_staging_workflow_on_backend
+
     def staging_identifier
       name[/.*:Staging:(.*)/, 1]
     end
@@ -146,5 +149,12 @@ def set_buildinfo
 
       @broken_packages.reject! { |package| package['state'] == 'unresolvable' } if @building_repositories.present?
     end
+
+    def update_staging_workflow_on_backend
+      return unless staging_workflow_id
+
+      staging_workflow.reload
+      staging_workflow.write_to_backend
+    end
   end
 end