[geary] client: remove unused mark_manual_* methods

[Cédric Bellegarde <cbellegarde src gnome org>]

commit 394895afdce69db3a82b0a8f75492c222262faf3
Author: Cédric Bellegarde <cedric bellegarde adishatz org>
Date:   Tue Sep 20 13:55:34 2022 +0200

    client: remove unused mark_manual_* methods
    
    See 8e9f00295e918888f72d5853f13e4048ae8d1a35

 .../conversation-viewer/conversation-list-box.vala   | 20 --------------------
 1 file changed, 20 deletions(-)
---
diff --git a/src/client/conversation-viewer/conversation-list-box.vala 
b/src/client/conversation-viewer/conversation-list-box.vala
index b8a7c0643..6688e2718 100644
--- a/src/client/conversation-viewer/conversation-list-box.vala
+++ b/src/client/conversation-viewer/conversation-list-box.vala
@@ -978,26 +978,6 @@ public class ConversationListBox : Gtk.ListBox, Geary.BaseInterface {
         this.mark_read_timer.start();
     }
 
-    /**
-     * Displays an email as being read, regardless of its actual flags.
-     */
-    public void mark_manual_read(Geary.EmailIdentifier id) {
-        EmailRow? row = this.email_rows.get(id);
-        if (row != null) {
-            row.view.is_manually_read = true;
-        }
-    }
-
-    /**
-     * Displays an email as being unread, regardless of its actual flags.
-     */
-    public void mark_manual_unread(Geary.EmailIdentifier id) {
-        EmailRow? row = this.email_rows.get(id);
-        if (row != null) {
-            row.view.is_manually_read = false;
-        }
-    }
-
     /** Adds an info bar to the given email, if any. */
     public void add_email_info_bar(Geary.EmailIdentifier id,
                                    Components.InfoBar info_bar) {