SupportDialog: Set ComponentBehavior

src/app/qml/SupportDialog.qml

@@ -1,6 +1,8 @@
 // SPDX-FileCopyrightText: 2026 Joshua Goins <josh@redstrate.com>
 // SPDX-License-Identifier: GPL-3.0-only
 
+pragma ComponentBehavior: Bound
+
 import QtQuick
 import QtQuick.Controls as QQC2
 import QtQuick.Layouts