Upgrade-14 fixups

[mhofman]

refs: #8755

Now layered on top of #8842

Description

Fixup a couple issues from #8755

• The function implementing the upgrade handler didn't get its name changed (no effect)
• Switch to the new "use layer" image of upgrade-13 as the base of the upgrade-14 a3p tests
  • Use images are currently broken (multiplatform images not building agoric-3-proposals#85), but a manual one is generated in https://github.com/Agoric/agoric-3-proposals/actions/runs/7733007365
• Remove leftover from the former docker upgrade-test

And a new feature:

• Trigger the core proposal from the upgrade handler instead of upgrade in (see Specify core proposals in upgrade handler #8843)

Security Considerations

None

Scaling Considerations

None

Documentation Considerations

None

Testing Considerations

Existing CI tests

Upgrade Considerations

Forces the wallet factory upgrade as part of the chain upgrade handler

[mhofman]

Putting back in draft until Agoric/agoric-3-proposals#85 is fixed

[mhofman]

PTAL @turadg

I am generating a use-upgrade-13 tag manually in https://github.com/Agoric/agoric-3-proposals/actions/runs/7733007365 in order to unblock from Agoric/agoric-3-proposals#85