Run sync-kernel.sh with stdin from /dev/null, so that any prompt asking
for human input fails the sync.
The exit code of sync-kernel.sh isn't reliable (e.g., it exits with 0
when interrupted), so tell from its output whether the sync went
through or there was nothing to sync.
On success, leave a bundle with the sync branch, patches and a pull
request description with the sync log in the output directory.
Assisted-by: Claude:claude-opus-5-5
Signed-off-by: Ihor Solodrai <ihor.solodrai@linux.dev>
