Seat: guard setFocusRaw() usage while locked

Focusing a layer shell or Xwayland override redirect surface while
locked is a bug.

river/Output.zig

@@ -293,6 +293,8 @@ pub fn arrangeLayers(self: *Self, target: ArrangeLayersTarget) void {
 
     if (target == .unmapped) return;
 
+    if (server.lock_manager.state != .unlocked) return;
+
     // Find the topmost layer surface in the top or overlay layers which
     // requests keyboard interactivity if any.
     const topmost_surface = outer: for (layers[0..2]) |layer| {

river/XwaylandOverrideRedirect.zig

@@ -101,6 +101,8 @@ pub fn handleMap(listener: *wl.Listener(*wlr.XwaylandSurface), xwayland_surface:
 }
 
 pub fn focusIfDesired(self: *Self) void {
+    if (server.lock_manager.state != .unlocked) return;
+
     if (self.xwayland_surface.overrideRedirectWantsFocus() and
         self.xwayland_surface.icccmInputModel() != .none)
     {