migration/options: Add x-ignore-shared This aids scriptings only. Reviewed-by: Fabiano Rosas <farosas@suse.de> Link: https://lore.kernel.org/r/20251205172054.288909-1-peterx@redhat.com [peterx: make the property x-ignore-shared to match, per cedric] [peterx: fix over-80 line] Signed-off-by: Peter Xu <peterx@redhat.com>