[gtksourceview] gutterlines: remove dead declaration

[Christian Hergert <chergert src gnome org>]

commit 85ac599ed2e522fc7cb2753577811811c92e69f4
Author: Christian Hergert <chergert redhat com>
Date:   Tue Mar 29 03:16:41 2022 -0700

    gutterlines: remove dead declaration
    
    This was never implemented, so it's safe to remove from the header.

 gtksourceview/gtksourcegutterlines.h | 5 -----
 1 file changed, 5 deletions(-)
---
diff --git a/gtksourceview/gtksourcegutterlines.h b/gtksourceview/gtksourcegutterlines.h
index d88513b1..cbf8c50f 100644
--- a/gtksourceview/gtksourcegutterlines.h
+++ b/gtksourceview/gtksourcegutterlines.h
@@ -48,11 +48,6 @@ GtkTextView   *gtk_source_gutter_lines_get_view         (GtkSourceGutterLines
 GTK_SOURCE_AVAILABLE_IN_ALL
 GtkTextBuffer *gtk_source_gutter_lines_get_buffer       (GtkSourceGutterLines                 *lines);
 GTK_SOURCE_AVAILABLE_IN_ALL
-void           gtk_source_gutter_lines_get_yrange       (GtkSourceGutterLines                 *lines,
-                                                         guint                                 line,
-                                                         guint                                *line_y,
-                                                         guint                                *line_height);
-GTK_SOURCE_AVAILABLE_IN_ALL
 void           gtk_source_gutter_lines_add_qclass       (GtkSourceGutterLines                 *lines,
                                                          guint                                 line,
                                                          GQuark                                qname);