vine: add --single-shot option to vine_factory

Proposed Changes

This PR enables users to add --single-shot option to vine_factory like

vine_factory -T condor -C factory.json --scratch-dir /scratch365/jzhou24/vine_scratch --debug-workers --single-shot

The previous way was:

vine_factory -T condor -C factory.json --scratch-dir /scratch365/jzhou24/vine_scratch --debug-workers -E --single-shot

The following items must be completed before PRs can be merge. Check these off to verify you have completed all steps.

[x] make test Run local tests prior to pushing.
[x] make format Format source code to comply with lint policies. Note that some lint errors can only be resolved manually (e.g., Python)
[x] make lint Run lint on source code prior to pushing.
[x] Manual Update Update the manual to reflect user-visible changes.
[x] Type Labels Select a github label for the type: bugfix, enhancement, etc.
[x] Product Labels Select a github label for the product: TaskVine, Makeflow, etc.
[x] PR RTM Mark your PR as ready to merge.