Since it is not possible to dynamically detect if a job is automatically
cancellable or not, a this new attribute is necessary. Moreover, it let
the maintainer of the repo to adjust the behaviour of the auto cancellation
feature to match exactly what he needs.

This is to accomodate prepended modules.

This commits avoiding conflicts between ArchiveTraceWorker
and ArchiveTracesCronWorker by changing the target of the
latter worker.

This toggles the ci_dag_support flag to be on by default.
This relies on ci_dag_limit_needs to be present to reduce
amount of inter-dependencies between jobs

This makes us to expand variables only when needed,
instead of requesting all variables each time.

This specifically helps in situation when explicit name
of `environment: production` is used.

When `needs:` is defined, the value of it is
not respected when returning a list of artifacts
to the runner from the job.