bpo-46850: Remove _PyEval_CallTracing() function (GH-32019)

Remove the private undocumented function _PyEval_CallTracing() from
the C API. Call the public sys.call_tracing() function instead.

Python/ceval.c

@@ -6708,16 +6708,19 @@ call_trace(Py_tracefunc func, PyObject *obj,
     return result;
 }
 
-PyObject *
+PyObject*
 _PyEval_CallTracing(PyObject *func, PyObject *args)
 {
+    // Save and disable tracing
     PyThreadState *tstate = _PyThreadState_GET();
     int save_tracing = tstate->tracing;
     int save_use_tracing = tstate->cframe->use_tracing;
-    PyObject *result;
-
     tstate->tracing = 0;
-    result = PyObject_Call(func, args, NULL);
+
+    // Call the tracing function
+    PyObject *result = PyObject_Call(func, args, NULL);
+
+    // Restore tracing
     tstate->tracing = save_tracing;
     tstate->cframe->use_tracing = save_use_tracing;
     return result;