Replace PyObject_CallFunctionObjArgs() with fastcall

* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)

PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.

_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.

This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.
diff --git a/Objects/unicodeobject.c b/Objects/unicodeobject.c
index 1c2257e..8f6f6c6 100644
--- a/Objects/unicodeobject.c
+++ b/Objects/unicodeobject.c
@@ -4269,7 +4269,7 @@
     if (*exceptionObject == NULL)
         goto onError;
 
-    restuple = PyObject_CallFunctionObjArgs(*errorHandler, *exceptionObject, NULL);
+    restuple = _PyObject_CallArg1(*errorHandler, *exceptionObject);
     if (restuple == NULL)
         goto onError;
     if (!PyTuple_Check(restuple)) {
@@ -4368,7 +4368,7 @@
     if (*exceptionObject == NULL)
         goto onError;
 
-    restuple = PyObject_CallFunctionObjArgs(*errorHandler, *exceptionObject, NULL);
+    restuple = _PyObject_CallArg1(*errorHandler, *exceptionObject);
     if (restuple == NULL)
         goto onError;
     if (!PyTuple_Check(restuple)) {
@@ -6649,8 +6649,7 @@
     if (*exceptionObject == NULL)
         return NULL;
 
-    restuple = PyObject_CallFunctionObjArgs(
-        *errorHandler, *exceptionObject, NULL);
+    restuple = _PyObject_CallArg1(*errorHandler, *exceptionObject);
     if (restuple == NULL)
         return NULL;
     if (!PyTuple_Check(restuple)) {
@@ -8644,8 +8643,7 @@
     if (*exceptionObject == NULL)
         return NULL;
 
-    restuple = PyObject_CallFunctionObjArgs(
-        *errorHandler, *exceptionObject, NULL);
+    restuple = _PyObject_CallArg1(*errorHandler, *exceptionObject);
     if (restuple == NULL)
         return NULL;
     if (!PyTuple_Check(restuple)) {