Use constant hash for Python's "None" object

This way, we don't need the "getPythonNone" function, which was only called once, to create the object. Beginning with Python 3.12, None will have a constant hash anyway. We use this new value. See python/cpython#99541.

Author: d-torrance

M2/Macaulay2/d/python.d

@@ -430,8 +430,8 @@ setupfun("pythonWrapM2Function", PyWrapM2Function);
 -- none --
 ----------
 
-PyNone(e:Expr):Expr := toExpr(Ccode(pythonObjectOrNull, "Py_None"));
-setupfun("getPythonNone", PyNone);
+setupconst("pythonNone",
+ Expr(pythonObjectCell(Ccode(pythonObject, "Py_None"), 0xFCA86420)));
 
 ---------------
 -- importing --

M2/Macaulay2/packages/Python.m2

@@ -69,7 +69,6 @@ exportFrom_Core {
  "objectType"}
 
 importFrom_Core {
- "getPythonNone",
  "pythonComplexFromDoubles",
  "pythonDictNew",
  "pythonDictSetItem",
@@ -81,6 +80,7 @@ importFrom_Core {
  "pythonLongFromLong",
  "pythonFloatAsDouble",
  "pythonFloatFromDouble",
+ "pythonNone",
  "pythonObjectGetAttrString",
  "pythonObjectHasAttrString",
  "pythonObjectRichCompareBool",
@@ -120,8 +120,6 @@ PythonObject#AfterPrint = x -> (
  t = replace("<([a-z]+) '(.*)'>"," of \\1 \\2",t);
  (PythonObject, t))
 
-pythonNone = getPythonNone()
-
 pythonValue = method(Dispatch => Thing)
 pythonValue String := s -> (
  if debugLevel > 0 then printerr("python command: ", s);