[REF] mail: remove unused code

part of task-2692836

closes odoo/odoo#91295

Signed-off-by: Sébastien Theys (seb) <seb@odoo.com>

addons/mail/static/src/models/user_setting.js

@@ -160,9 +160,6 @@ registerModel({
                 this._saveSettings();
             }
         },
-        toggleLayoutSettingsWindow() {
-            this.update({ isRtcLayoutSettingDialogOpen: !this.isRtcLayoutSettingDialogOpen });
-        },
         /**
          * toggles the display of the option window
          */
@@ -269,12 +266,6 @@ registerModel({
             readonly: true,
             required: true,
         }),
-        /**
-         * true if the dialog for the call viewer layout is open
-         */
-        isRtcLayoutSettingDialogOpen: attr({
-            default: false,
-        }),
         /**
          * Formatted string that represent the push to talk key with its modifiers.
          */