QQuickTreeView: add missing \since 6.4 lines

Change-Id: I5cec24e231c9dc22d384afa5716a1758f59c0311
Reviewed-by: Mitch Curtis <mitch.curtis@qt.io>

src/quick/items/qquicktreeview.cpp

@@ -154,6 +154,7 @@
 
 /*!
     \qmlmethod QtQuick::TreeView::expandRecursively(row = -1, depth = -1)
+    \since 6.4
 
     Expands the tree node at the given \a row in the view recursively down to
     \a depth. \a depth should be relative to the depth of \a row. If
@@ -189,6 +190,7 @@
 
 /*!
     \qmlmethod QtQuick::TreeView::collapseRecursively(row = -1)
+    \since 6.4
 
     Collapses the tree node at the given \a row in the view recursively down to
     all leaves.