Node -> Edge typo (#393)

Co-authored-by: grace-harper <[email protected]>

src/qiskit_qec/utils/decoding_graph_attributes.py

@@ -133,7 +133,7 @@ def __setitem__(self, key, value):
             self.properties[key] = value
 
     def __eq__(self, rhs) -> bool:
-        if not isinstance(rhs, DecodingGraphNode):
+        if not isinstance(rhs, DecodingGraphEdge):
             return NotImplemented
 
         return set(self.qubits) == set(rhs.qubits) and self.weight == rhs.weight