Silence stderr output on *BSD

[frenkel]

Without this, all my cronjobs, servers etc will always output to stderr:

hostname: unknown option -- f
usage: hostname [-s] [name-of-host]

[CLAassistant]

All committers have signed the CLA.

[kaylareopelle]

Thanks for your submission, @frenkel! Our team is discussing your contribution internally and will be back in touch with more details soon.

[kaylareopelle]

@angelatan2, @fallwith - Let's take a look at the failed .github/workflows/label_community_cards.yml build tomorrow

[kaylareopelle]

Hi @frenkel! We've decided to add this to our codebase. Before we merge it in, could you let us know what specific BSD you encountered this issue on?

[frenkel]

Hi @kaylareopelle, great to hear! I’ve seen this on OpenBSD and it fixes the issue there. Thanks!

[fallwith]

Thank you, @frenkel - OpenBSD's hostname definitely doesn't support the -f switch. Merging.

For posterity for future reviewers who come across this PR:

• We probably should standardize on the use of a CLI helper that automatically handles stderr, but for now there is already precedent for the use of directing to /dev/null elsewhere in the codebase.
• The lone CI check failure was related to the automated labeler not being able to apply a label (write access) when ran from a fork (known GitHub Actions issue with various workarounds)

[fallwith]

This change has been released in agent v8.5.0, available now from RubyGems.org