CI: icmd is not usable to test when binary expect a console

[apostasie]

Description

icmd passes an io.Multiwriter for stdout and stderr of the underlying command.

So (even if stdout is a proper pty), the command will still bail out if it requires a console (because "inappropriate ioctl for device").

That, along with the gymnastic in containerd/console - took me half a day to figure out why the eff I would not get anything on out with attach tests.

I am not sure we should continue using icmd.
The added value of it is rather limited (literally a few dozens lines of code that we are still using) , and I am not particularly interested in going over there to hack on it.

I will bypass it so that we can get #3591 in either way, so, might be time to bite the bullet and ditch it.

Steps to reproduce the issue

Describe the results you received and expected

na

What version of nerdctl are you using?

main

Are you using a variant of nerdctl? (e.g., Rancher Desktop)

None

Host information

No response

[apostasie]

/dibs

I'll get us away from icmd once I am done with the CI-build series.

@AkihiroSuda can you assign?