qapi: fix device-sync-config since-version

Actually it comes in 9.2, not 9.1.

Fixes: 3f98408e2e ("qapi: introduce device-sync-config")
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@yandex-team.ru>
Message-Id: <20241108071957.727286-1-vsementsov@yandex-team.ru>
Reviewed-by: Michael S. Tsirkin <mst@redhat.com>
Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

qapi/qdev.json

@@ -182,7 +182,7 @@
 #
 # @unstable: The command is experimental.
 #
-# Since: 9.1
+# Since: 9.2
 ##
 { 'command': 'device-sync-config',
   'features': [ 'unstable' ],