Description

Change how multiple inventory sources are synced.

Summary

Currently, if you have multiple inventory sources for an inventory, they are synced individually.
This leads to:

• confusing (and potentially deadlock-y) behavior
• a difference to how multiple inventory sources are used when you do it on the command line

We should move to not doing individual inventory source syncs. Instead, we should, when an inventory is synced, run a single ansible-inventory process passing all inventory sources.

Note: this will be a behavior change that will change how inventory is computed. It will also change the mechanism such that "overwrite" and "overwrite vars" should not be used for individual sources.

Upstream : https://github.com/ansible/awx/issues/3769