t/lib-gpg: fix ssh-keygen -Y check-novalidate with openssh-9.0
OpenSSH-9.0 requires a namespace option with `-Y check-novalidate`.
This was added in openssh-portable commit
a0b5816f8 (upstream:
ssh-keygen -Y check-novalidate requires namespace or SEGV, 2022-03-18).
The -n option was documented as a required option since check-novalidate
was added in openssh-portable
8aa2aa3cd (upstream: Allow testing
signature syntax and validity without verifying, 2019-09-16).
Signed-off-by: Todd Zullinger <tmz@pobox.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>