Build tempest and the plugins projects

To build tempest and plugins projects, we need to proceed as below:

1. Branch and build the tempest package (i.e the core package, not the plugins) with bootstrap mode enabled
   e.g: https://review.rdoproject.org/r/c/openstack/tempest-distgit/+/45062
2. Disable the bootstrap mode without bumping release in order to provide openstack-tempest-all in RDO trunk, while awaiting the plugins to be built in CBS.
   e.g: https://review.rdoproject.org/r/c/openstack/tempest-distgit/+/45203
3. Cut rpm-master branch to create <release>-rdo branch in associated distgit plugins projects
   e.g: https://review.rdoproject.org/r/c/config/+/45313
4. Pin the plugins in rdoinfo
   e.g: https://review.rdoproject.org/r/c/rdoinfo/+/45314
5. Review and merge the patches automatically created by our bot
6. Bump the release in tempest project and build it (it's the follow-up of 2.)
   e.g: https://review.rdoproject.org/r/c/openstack/tempest-distgit/+/45418

It's important to branch before the pin to ensure the patches automated submission.