Remove deprecated top-level `classicalfunction` imports (#11486)

* Remove deprecated top-level classicalfunction imports

* add reno

* new editor does not automatically run black yet... sorry

* Update releasenotes/notes/remove-cfun-toplevel-5d0d58bed83d57ed.yaml

Co-authored-by: Jake Lishman <jake@binhbar.com>

---------

Co-authored-by: Jake Lishman <jake@binhbar.com>

qiskit/circuit/__init__.py

@@ -398,28 +398,3 @@ from .controlflow import (
     BreakLoopOp,
     ContinueLoopOp,
 )
-
-
-_DEPRECATED_NAMES = {
-    "Int1": "qiskit.circuit.classicalfunction.types",
-    "Int2": "qiskit.circuit.classicalfunction.types",
-    "classical_function": "qiskit.circuit.classicalfunction",
-    "BooleanExpression": "qiskit.circuit.classicalfunction",
-}
-
-
-def __getattr__(name):
-    if name in _DEPRECATED_NAMES:
-        import importlib
-        import warnings
-
-        module_name = _DEPRECATED_NAMES[name]
-        warnings.warn(
-            f"Accessing '{name}' from '{__name__}' is deprecated since Qiskit Terra 0.22 "
-            f"and will be removed in 0.23.  Import from '{module_name}' instead. "
-            "This will require installing 'tweedledum' as an optional dependency from Terra 0.23.",
-            DeprecationWarning,
-            stacklevel=2,
-        )
-        return getattr(importlib.import_module(module_name), name)
-    raise AttributeError(f"module '{__name__}' has no attribute '{name}'")

releasenotes/notes/remove-cfun-toplevel-5d0d58bed83d57ed.yaml

@@ -0,0 +1,6 @@
+---
+upgrade:
+  - |
+    Importing :class:`.Int1`, :class:`.Int2`, :class:`.BooleanFunction`, :func:`.classical_function`
+    from :mod:`qiskit.circuit` is now disabled. Instead, import the objects from the
+    :mod:`qiskit.circuit.classicalfunction` submodule, which requires the ``tweedledum`` package.