The unused parameter dag in DAGNode constructor is removed (Qiskit#13863)

* The unused parameter dag in DAGNode constructor is removed

* Update crates/circuit/src/dag_node.rs

Co-authored-by: Matthew Treinish <[email protected]>

* remove internal usage

* Update releasenotes/notes/removal_13022-13f237b337e3d5fb.yaml

---------

Co-authored-by: Matthew Treinish <[email protected]>

Author: 1ucian0

crates/circuit/src/dag_node.rs

@@ -119,13 +119,12 @@ pub struct DAGOpNode {
 #[pymethods]
 impl DAGOpNode {
     #[new]
-    #[pyo3(signature = (op, qargs=None, cargs=None, *, dag=None))]
+    #[pyo3(signature = (op, qargs=None, cargs=None))]
     pub fn py_new(
         py: Python,
         op: Bound<PyAny>,
         qargs: Option<TupleLikeArg>,
         cargs: Option<TupleLikeArg>,
-        #[allow(unused_variables)] dag: Option<Bound<PyAny>>,
     ) -> PyResult<Py<Self>> {
         let py_op = op.extract::<OperationFromPython>()?;
         let qargs = qargs.map_or_else(|| PyTuple::empty(py), |q| q.value);

qiskit/dagcircuit/dagdependency_v2.py

@@ -345,7 +345,6 @@ def apply_operation_back(self, operation, qargs=(), cargs=()):
             op=operation,
             qargs=qargs,
             cargs=cargs,
-            dag=self,
         )
         new_node._node_id = self._multi_graph.add_node(new_node)
         self._update_edges()

releasenotes/notes/removal_13022-13f237b337e3d5fb.yaml

@@ -0,0 +1,7 @@
+---
+upgrade_circuits:
+  - |
+    The deprecated argument ``.dag`` for :class:`.DAGNode` and its subclasses :class:`.DAGOpNode`,
+    :class:`.DAGOutNode`, and :class:`.DAGInNode`.  ``dag`` was optional parameter when constructing
+    these objects that was unused and ignored since the 1.3.0 release. The parameter was deprecated
+    in 1.4 and has now been is removed.