Bit.index is deprecated since Apr 2021 (#733)

Co-authored-by: Kevin Tian <kevin.tian@ibm.com>

qiskit_ibm_provider/transpiler/passes/scheduling/dynamical_decoupling.py

@@ -503,7 +503,7 @@ def _constrained_length(values: np.array) -> np.array:
                 return self._alignment * np.floor(values / self._alignment)
 
             if self._coupling_map:
-                if self._coupling_coloring[qubit.index] == 0:
+                if self._coupling_coloring[self._dag.qubits.index(qubit)] == 0:
                     sub_spacings = spacings
                 else:
                     sub_spacings = alt_spacings