branch cut jobs: do not create tag per build
The git
DSL method that was being used previously added a default
to create a pre-build tag, but we don't have a default user
configured for the git plugin. This causes builds to fail.
The pre-build tag is not something we had in the jobs when we defined
them manually and we don't need it. Removed by using a different
git
DSL method that accepts a closure to explicitly configure all
the options.