Update checkpoint script & workflow

[kinow]

Describe the bug

It's not possible to re-generate the current checkpoint workflow, one. The script uses cylc reg/cylc run, which will need to be replaced by cylc install/cylc play.

Furthermore, there's also an issue that recent changes to Cylc Flow (probably related to SoD or event-driven?) changed the output of the checkpoint task, which doesn't include the GOOD family anymore.

Release version(s) and/or repository branch(es) affected?

master

Steps to reproduce the bug

Run the generate script, compare with previous output that contains the GOOD family.

Expected behavior

Output similar to previous output, not necessarily identical due to #559 , but still structurally similar.

Screenshots

Additional context

This is also blocking #543 (comment) as the tests expect the GOOD family in one e2e test (one example, but there are other tests that expect the structure to be the same).

Pull requests welcome!
This is an Open Source project - please consider contributing a bug fix
yourself (please read CONTRIBUTING.md before starting any work though).

[oliver-sanders]

I think at this stage it looks like hand editing the offline data is the way to go.

So closing this one for now, we may re-visit auto-generating it at a future point.