Fix build with pre-C23 compilers:

error: parameter name omitted

https://gitlab.gnome.org/GNOME/libnotify/-/issues/67
--- libnotify/launch-context.c.orig	2026-01-08 21:16:29.000000000 -0600
+++ libnotify/launch-context.c	2026-04-21 01:56:28.000000000 -0500
@@ -49,8 +49,8 @@
 
 static char *
 notification_app_launch_context_get_startup_notify_id (GAppLaunchContext *context,
-                                                       GAppInfo *,
-                                                       GList *)
+                                                       GAppInfo *i,
+                                                       GList *l)
 {
         NotificationAppLaunchContext *self = NOTIFICATION_APP_LAUNCH_CONTEXT (context);