Advertise wl_seat version 7
This does not require any code changes, as we already copy the keymap
data separately for each client.
For details, see
#include "types/wlr_seat.h"
#include "util/signal.h"
-#define SEAT_VERSION 6
+#define SEAT_VERSION 7
static void seat_handle_get_pointer(struct wl_client *client,
struct wl_resource *seat_resource, uint32_t id) {
