u19 is not acceptance tested

[mhofman]

Describe the bug

Because of the delay (and rescoping) in u18 release, u19 core proposals were excluded from upgrade.go and were tested as core eval submissions in a p:upgrade-19 a3p-integration test. However most of these core proposals were not submitted during the eval.sh phase, and instead were submitted during a test.sh phase, which means the z:acceptance layer was not testing the outcome of the u19 core proposals.

Expected behavior

u19 core proposals running as part of a chain software upgrade (upgrade.go) on top of u18, or if #10839 is not merged yet, making sure they're sent as part of the eval.sh stage.

Platform Environment

CI / a3p-integration