Remove deprecated code

constraints.txt

@@ -1,2 +1,3 @@
 numpy>=1.20.0
 ipython<8.13;python_version<'3.9'
+

qiskit_machine_learning/algorithms/classifiers/vqc.py

@@ -20,7 +20,7 @@
 from qiskit.algorithms.optimizers import Optimizer, OptimizerResult, Minimizer
 from qiskit.primitives import BaseSampler
 
-from ...neural_networks import CircuitQNN, SamplerQNN
+from ...neural_networks import SamplerQNN
 from ...utils import derive_num_qubits_feature_map_ansatz
 from ...utils.loss_functions import Loss
 
@@ -158,7 +158,7 @@ def _fit_internal(self, X: np.ndarray, y: np.ndarray) -> OptimizerResult:
         num_classes = self._num_classes
 
         # instance check required by mypy (alternative to cast)
-        if isinstance(self._neural_network, (CircuitQNN, SamplerQNN)):
+        if isinstance(self._neural_network, SamplerQNN):
             self._neural_network.set_interpret(self._get_interpret(num_classes), num_classes)
 
         function = self._create_objective(X, y)

qiskit_machine_learning/algorithms/regressors/vqr.py

@@ -17,7 +17,6 @@
 import numpy as np
 from qiskit import QuantumCircuit
 from qiskit.algorithms.optimizers import Optimizer, Minimizer
-from qiskit.opflow import PauliSumOp
 from qiskit.primitives import BaseEstimator
 from qiskit.quantum_info.operators.base_operator import BaseOperator
 
@@ -35,7 +34,7 @@ def __init__(
         num_qubits: int | None = None,
         feature_map: QuantumCircuit | None = None,
         ansatz: QuantumCircuit | None = None,
-        observable: BaseOperator | PauliSumOp | None = None,
+        observable: BaseOperator | None = None,
         loss: str | Loss = "squared_error",
         optimizer: Optimizer | Minimizer | None = None,
         warm_start: bool = False,
@@ -81,10 +80,10 @@ def __init__(
                 can't be adjusted to ``num_qubits``.
             ValueError: if the type of the observable is not compatible with ``estimator``.
         """
-        if observable is not None and not isinstance(observable, (BaseOperator, PauliSumOp)):
+        if observable is not None and not isinstance(observable, BaseOperator):
             raise ValueError(
                 f"Unsupported type of the observable, expected "
-                f"'BaseOperator | PauliSumOp', got {type(observable)}"
+                f"'BaseOperator', got {type(observable)}"
             )
 
         self._estimator = estimator