"transactional-update run" does not propagate command error exit codes to host

[ipetrov117]

Currently commands executed through transactional-update run do not have their non-zero exit codes propagated to the host.

This results in transactional-update run always returning a zero exit code even for obviously failing commands.

Example:

# transactional-update run ls /foo/bar
Checking for newer version.
transactional-update 4.8.1 started
Options: run ls /foo/bar
Separate /var detected.
2024-10-16 08:08:56 tukit 4.8.1 started
2024-10-16 08:08:56 Options: -c4 open 
2024-10-16 08:08:57 Using snapshot 4 as base for new snapshot 15.
2024-10-16 08:08:57 /var/lib/overlay/4/etc
2024-10-16 08:08:57 Syncing /etc of previous snapshot 3 as base into new snapshot "/.snapshots/15/snapshot"
2024-10-16 08:08:57 SELinux is enabled.
ID: 15
2024-10-16 08:08:58 Transaction completed.
2024-10-16 08:08:58 tukit 4.8.1 started
2024-10-16 08:08:58 Options: call 15 ls /foo/bar 
2024-10-16 08:08:58 Executing `ls /foo/bar`:
ls: cannot access '/foo/bar': No such file or directory
2024-10-16 08:08:58 Application returned with exit status 2.
2024-10-16 08:08:58 tukit 4.8.1 started
2024-10-16 08:08:58 Options: close 15 
2024-10-16 08:09:00 New default snapshot is #15 (/.snapshots/15/snapshot).
2024-10-16 08:09:00 Transaction completed.
...
New default snapshot is #15 (/.snapshots/15/snapshot).
transactional-update finished

# echo $?
0

Furthermore, this also creates a new snapshot, when it should in fact discard the snapshot.