Investigate and fix CI create DB error

[marcua]

Starting with Ubuntu 24.x, nsjail can no longer work with the default security permissions. We'll have to consider a solution for the long-term, but in the short-term, the solution on CI is to turn off some AppArmor protections.

In debugging this issue, I realized that we weren't properly handling the case where the isolated query runner was returning an error that couldn't be parsed as an AybError, so resolved that as well.

[marcua]

It's this:

Which is this

to-do

• Clean up JSON parsing logic so we still try to parse an AybError and only on failure do we share the unparsed error
• Try this from the issue (but probably have to migrate off of nsjail eventually)

sudo sysctl -w kernel.apparmor_restrict_unprivileged_unconfined=0
sudo sysctl -w kernel.apparmor_restrict_unprivileged_userns=0