misc: print script logs upon failure

[Nashtare]

We used to have ./script.sh | tee log.out for convenience to retrieve the errors arising in CI jobs, but this was quite cumbersome locally for quick testing runs, hence reverting to &> log.out, which obfuscates everything.

As a simple middle ground, we can print the logs only upon failure, to easily retrieve the failures on the CI while not clogging our terminals when testing