Simplify python class construction

Since this PR was first written the split between the python side and
rust side of the CommutationChecker class has changed so that there are
no longer separate classes anymore. The implementations are unified and
the python space class just wraps an inner rust object. However, the
construction of the CommutationAnalysis pass was still written assuming
there was the possibility to get either a rust or Python object. This
commit fixes this and the type change on the `comm_checker` attribute by
removing the unnecessary logic.

qiskit/transpiler/passes/optimization/commutation_analysis.py

@@ -13,7 +13,6 @@
 """Analysis pass to find commutation relations between DAG nodes."""
 
 from qiskit.circuit.commutation_library import SessionCommutationChecker as scc
-from qiskit.circuit.commutation_checker import CommutationChecker as PyCommutationChecker
 from qiskit.transpiler.basepasses import AnalysisPass
 from qiskit._accelerate.commutation_analysis import analyze_commutations
 
@@ -33,12 +32,6 @@ def __init__(self, *, _commutation_checker=None):
         if _commutation_checker is None:
             _commutation_checker = scc
 
-        if isinstance(_commutation_checker, PyCommutationChecker):
-            # If an instance of the to-be deprecated Python implementation of the CommutationChecker
-            # is passed, defer to the internally held Rust implementation instead. This is needed
-            # as the ``analyze_commutations`` function expects the Rust implementation.
-            _commutation_checker = _commutation_checker.cc
-
         self.comm_checker = _commutation_checker
 
     def run(self, dag):
@@ -48,4 +41,4 @@ def run(self, dag):
         into the ``property_set``.
         """
         # Initiate the commutation set
-        self.property_set["commutation_set"] = analyze_commutations(dag, self.comm_checker)
+        self.property_set["commutation_set"] = analyze_commutations(dag, self.comm_checker.cc)