refact(net): drop old dag nx-package

Author: ankostis

graphkit/network.py

@@ -108,7 +108,7 @@ def compile(self):
         self.steps = []
 
         # create an execution order such that each layer's needs are provided.
-        ordered_nodes = list(nx.dag.topological_sort(self.graph))
+        ordered_nodes = list(nx.topological_sort(self.graph))
 
         # add Operations evaluation steps, and instructions to free data.
         for i, node in enumerate(ordered_nodes):