Decidim seeds take too much time

[Quentinchampenois]

Describe the bug
A clear and concise description of what the bug is.

Seeds runs for at least 10 minutes, it is slightly longer than on previous versions.

To Reproduce
Steps to reproduce the behavior:

1. Seed a database bundle exec rake db:seed

Expected behavior
A clear and concise description of what you expected to happen.

We should investigate on what are the reasons and how to reduce maximum time to 2 minutes