fab: build images with user dockerpkg-builder
To avoid issues caused by git when a repository is shared between
multiple users, switch the deployment to use a shared system user
dockerpkg-builder
.
That:
- addresses potential permission problems (T277604, T338277) and
avoid having to use git
safe.directory
(T335354). - align with how the releng CI images are build (with the shared user
zuul
).
The system user was introduced by https://gerrit.wikimedia.org/r/c/operations/puppet/+/927975
Bug: T277604
Bug: T338277
Bug: T335354