A large customer installation has reported issues with the migrations contained in 13.0.

We can improve several things:

* [x] Inform about statement timeouts and how to increase them [https://www.openproject.org/docs/installation-and-operations/operation/upgrading/](https://www.openproject.org/docs/installation-and-operations/operation/upgrading/)
* Begin of the insertion[x]End of the insertion Begin of the deletion [ ]End of the deletion Run migrations with higher or indefinite timeout by default
* [ ] Inform in release notes and other channels about longer running migrations and how to prepare them.