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 <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: tmzullinger

t/lib-gpg.sh

@@ -136,7 +136,7 @@ test_lazy_prereq GPGSSH '
 
 test_lazy_prereq GPGSSH_VERIFYTIME '
 	# Check if ssh-keygen has a verify-time option by passing an invalid date to it
-	ssh-keygen -Overify-time=INVALID -Y check-novalidate -s doesnotmatter 2>&1 | grep -q -F "Invalid \"verify-time\"" &&
+	ssh-keygen -Overify-time=INVALID -Y check-novalidate -n "git" -s doesnotmatter 2>&1 | grep -q -F "Invalid \"verify-time\"" &&
 
 	# Set up keys with key lifetimes
 	ssh-keygen -t ed25519 -N "" -C "timeboxed valid key" -f "${GPGSSH_KEY_TIMEBOXEDVALID}" >/dev/null &&