The prepare stage runs "echo "Running on $(hostname)...""[1], resulting
in "bash: line 7: hostname: command not found" and it outputting
"Running on ..." as the hostname command is provided by inetutils, which
is not installed.

Fix it by "monkey patching" it to use "hostnamectl hostname" and inject
the hostname with SMBIOS[2][3]. Injecting creds with SMBIOS may also be
useful in the future, e.g. for injecting an ephemeral SSH public key.

[1] https://gitlab.com/gitlab-org/gitlab-runner/-/blob/v17.5.2/shells/bash.go?ref_type=tags#L452-L456
[2] https://systemd.io/CREDENTIALS/
[3] https://github.com/systemd/systemd/pull/30814