Skip transaction check for seeding burndown charts

The seed-fu gem wraps all seeds in a transaction:
https://github.com/mbleigh/seed-fu/blob/34c054c914858c3d7685f83d16dea5c0e2114561/lib/seed-fu/runner.rb#L35.
We can skip the Sidekiq transaction check for seeding test fixtures.

Closes https://gitlab.com/gitlab-org/gitlab-development-kit/issues/351

db/fixtures/development/20_burndown.rb

@@ -9,18 +9,20 @@ class Gitlab::Seeder::Burndown
   def seed!
     Timecop.travel 10.days.ago
 
-    Sidekiq::Testing.inline! do
-      create_milestone
-      puts '.'
+    Sidekiq::Worker.skipping_transaction_check do
+      Sidekiq::Testing.inline! do
+        create_milestone
+        puts '.'
 
-      create_issues
-      puts '.'
+        create_issues
+        puts '.'
 
-      close_issues
-      puts '.'
+        close_issues
+        puts '.'
 
-      reopen_issues
-      puts '.'
+        reopen_issues
+        puts '.'
+      end
     end
 
     Timecop.return