Fixing smoke test failures

[OliviaLynn]

Problem & Solution Description (including issue #)

Should fix the rail smoke test failures (when all the following conditions are completed)

Context:

The canary in the mine was Useful_Utilities, which was failing with NameError: name 'RailStage' is not defined at this point in this run.

Main change: RailStage import

• RailStage is now accessed via rail.core.stage.RailStage (previously rail.core.RailStage)
• We don't seem to get RailStage when we run import_and_attach_all anymore
• There could be some way to still get this, but for the time being, I think it should be fine to access RailStage via rail.core.stage.RailStage or import it as from rail.core.stage import RailStage or such

Also: ceci pre-v2 rollback

• I've temporarily added a step to the smoke_test workflow to roll back ceci to be pre-v2, as that introduced a new error to the mix today (and Joe has said we shouldn't be using ceci v2 yet)
• I don't mind a different strategy for this, but figured pinning a pre-v2 version in the dependencies would require us to roll out a new release, which would get in the way of things. I'm making/self-assigning Self-Memo: check ceci status and remove rollback step when appropriate #151 on my radar.

Finally: PZFlow import

• I believe (/am hoping) the remaining error will be fixed with this pzflow update I have in this other PR:
• Update pzflow to pzflow_nf in import rail_pzflow#14

[ztq1996]

Looks good, thank you for catching the error

[jlvdb]

I should have pointed this out here directly, you could also add a line to pyproject.toml which says

ceci!=2.0

which avoids the issue with remembering to switch back to the latest version.

[hangqianjun]

We are working on updating everything to ceci v2 now. This PR (LSSTDESC/rail_base#132) should hopefully resolve the problem without making changes.