local and global artifacts job configs have inconsistent names

[Gankra]

I didn't really notice at the time, but the docs for custom build jobs say that "build-local-artifacts-jobs" and "build-global-artifacts-jobs" are the names of these configs, but in fact they're "local-artifacts-jobs" and "global-artifacts-jobs".

The actual builtin CI task is "build-local-artifacts" and "build-global-artifacts", so the docs have the more consistent name. However, I'm coming around to a belief that these should be renamed to just "build-local" and "build-global" because "artifacts" is redundant and crowds out precious space in various UIs. (and then the config would be "build-local-jobs" and "build-global-jobs")

tbc this is "we have 2 names and i hate them both, let's use this 3rd name" (we can add as many aliases as we want for the configs)

[Gankra]

This will be fixed as part of #841