Explicitly destroy webhooks and logs before the project deletion

Contributes to https://gitlab.com/gitlab-org/gitlab/-/issues/328393

Remove feature flag `destroy_webhooks_before_the_project`

Changelog: other

app/services/projects/destroy_service.rb

@@ -116,7 +116,7 @@ module Projects
       log_destroy_event
       trash_relation_repositories!
       trash_project_repositories!
-      destroy_web_hooks! if Feature.enabled?(:destroy_webhooks_before_the_project, project, default_enabled: :yaml)
+      destroy_web_hooks!
 
       # Rails attempts to load all related records into memory before
       # destroying: https://github.com/rails/rails/issues/22510

config/feature_flags/development/destroy_webhooks_before_the_project.yml

----
-name: destroy_webhooks_before_the_project
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/59754
-rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/328393
-milestone: '13.12'
-type: development
-group: group::source code
-default_enabled: true

spec/services/projects/destroy_service_spec.rb

@@ -447,23 +447,6 @@ RSpec.describe Projects::DestroyService, :aggregate_failures do
 
       it_behaves_like 'handles errors thrown during async destroy', "Failed to remove webhooks"
     end
-
-    context 'when "destroy_webhooks_before_the_project" flag is disabled' do
-      before do
-        stub_feature_flags(destroy_webhooks_before_the_project: false)
-      end
-
-      it 'does not call WebHooks::DestroyService' do
-        expect(WebHooks::DestroyService).not_to receive(:new)
-
-        expect do
-          destroy_project(project, user)
-        end.to change(WebHook, :count).by(-2)
-           .and change(WebHookLog, :count).by(-1)
-
-        expect(another_project_web_hook.reload).to be
-      end
-    end
   end
 
   context 'error while destroying', :sidekiq_inline do