[gtksourceview] vapi: mark CompletionProvider methods as virtual

[Christian Hergert <chergert src gnome org>]

commit adbf604572f0c6aace0dd36b3ff325bc517cef37
Author: Christian Hergert <chergert redhat com>
Date:   Mon Sep 5 16:53:03 2022 -0700

    vapi: mark CompletionProvider methods as virtual

 gtksourceview/GtkSource-5.metadata | 6 ++++++
 1 file changed, 6 insertions(+)
---
diff --git a/gtksourceview/GtkSource-5.metadata b/gtksourceview/GtkSource-5.metadata
index 83c010d6..88fa03d7 100644
--- a/gtksourceview/GtkSource-5.metadata
+++ b/gtksourceview/GtkSource-5.metadata
@@ -1,2 +1,8 @@
 CompletionProposal
   .get_typed_text#virtual_method virtual
+CompletionProvider
+  .get_title#virtual_method virtual
+  .get_priority#virtual_method virtual
+  .is_trigger#virtual_method virtual
+  .key_activates#virtual_method virtual
+  .list_alternates#virtual_method virtual
\ No newline at end of file