"sampler" is currently a keyword argument for QNSPSA (#218)

Co-authored-by: Steve Wood <40241007+woodsp-ibm@users.noreply.github.com>

Author: julenl

qiskit_algorithms/optimizers/qnspsa.py

@@ -1,6 +1,6 @@
 # This code is part of a Qiskit project.
 #
-# (C) Copyright IBM 2021, 2024.
+# (C) Copyright IBM 2021, 2025.
 #
 # This code is licensed under the Apache License, Version 2.0. You may
 # obtain a copy of this license in the LICENSE.txt file in the root directory
@@ -232,8 +232,7 @@ def settings(self) -> dict[str, Any]:
     @staticmethod
     def get_fidelity(
         circuit: QuantumCircuit,
-        *,
-        sampler: BaseSampler | None = None,
+        sampler: BaseSampler,
     ) -> Callable[[np.ndarray, np.ndarray], float]:
         r"""Get a function to compute the fidelity of ``circuit`` with itself.
 

releasenotes/notes/sampler_as_positional_arg_for_qnspsa-2efca170947f3cd7.yaml

@@ -0,0 +1,7 @@
+---
+upgrade:
+  - |
+    The list of arguments for `QNSPSA.get_fidelity()` has been updated to
+    remove the keyword enforcement for `sampler` so also allowing it now
+    as positional. Additionally the `sampler` must be explicitly specified, as a
+    valid object, as it no longer supports `None` nor defaults to that.