IVGCVSW-7635 Remove deprecated code due to be removed in 23.08 (SubgraphView)

Signed-off-by: Francis Murtagh <francis.murtagh@arm.com>
Signed-off-by: Kevin May <kevin.may@arm.com>
Change-Id: I6686ad0a16ef763dbdc771c7ef792ae2890e0ab2
diff --git a/src/armnn/Network.cpp b/src/armnn/Network.cpp
index 3074c1f..4111147 100644
--- a/src/armnn/Network.cpp
+++ b/src/armnn/Network.cpp
@@ -1270,8 +1270,8 @@
                                   SubgraphView& subgraph,
                                   Optional<std::vector<std::string>&> errMessages)
 {
-    SubgraphView::IConnectableLayerIterator firstLayer = subgraph.beginIConnectable();
-    SubgraphView::IConnectableLayerIterator lastLayer  = subgraph.endIConnectable();
+    SubgraphView::IConnectableLayerIterator firstLayer = subgraph.begin();
+    SubgraphView::IConnectableLayerIterator lastLayer  = subgraph.end();
     return AssignBackends(optNetObjPtr,
                           backendSettings,
                           firstLayer,