meta: Silence a couple of introspection warnings

We could just avoid introspecting `meta-startup-notification.h`, but
that'd mean splitting up the header list. Just silence the warning
instead.

src/meta/display.h

@@ -224,6 +224,10 @@ typedef enum
 } MetaDisplayCorner;
 
 MetaWorkspaceManager *meta_display_get_workspace_manager (MetaDisplay *display);
+
+/**
+ * meta_display_get_startup_notification: (skip)
+ */
 MetaStartupNotification * meta_display_get_startup_notification (MetaDisplay *display);
 
 #endif

src/meta/meta-startup-notification.h

@@ -27,6 +27,9 @@ typedef struct _MetaStartupSequence MetaStartupSequence;
 
 GType         meta_startup_notification_get_type      (void);
 
+/**
+ * meta_startup_notification_get_sequences: (skip)
+ */
 GSList *      meta_startup_notification_get_sequences (MetaStartupNotification *sn);
 
 GType         meta_startup_sequence_get_type          (void);