Check for dirtied items in the cluster

When drawing the ratsnest, we need to be careful to avoid accessing
CONN_ITEMs that have been changed by the underlying model.  Checking for
dirty items instead of valid items will prevent us looking at data that
are out of date

Fixes https://gitlab.com/kicad/code/kicad/issues/14265

(cherry picked from commit 283770fc45)

pcbnew/board.cpp

@@ -290,7 +290,7 @@ void BOARD::UpdateRatsnestExclusions()
             [&]( CN_EDGE& aEdge )
             {
                 if( aEdge.GetSourceNode() && aEdge.GetTargetNode()
-                    && aEdge.GetSourceNode()->Valid() && aEdge.GetTargetNode()->Valid() )
+                    && !aEdge.GetSourceNode()->Dirty() && !aEdge.GetTargetNode()->Dirty() )
                 {
                     std::pair<KIID, KIID> ids = { aEdge.GetSourceNode()->Parent()->m_Uuid,
                                                   aEdge.GetTargetNode()->Parent()->m_Uuid };

pcbnew/connectivity/connectivity_items.cpp

@@ -275,6 +275,12 @@ bool CN_ANCHOR::Valid() const
 }
 
 
+bool CN_ANCHOR::Dirty() const
+{
+    return !Valid() ||  m_item->Dirty();
+}
+
+
 bool CN_ANCHOR::IsDangling() const
 {
     int accuracy = 0;

pcbnew/connectivity/connectivity_items.h

@@ -72,6 +72,8 @@ public:
 
     bool Valid() const;
 
+    bool Dirty() const;
+
     CN_ITEM* Item() const
     {
         return m_item;