*: keep using func_code and not yet __code__ with scripts

On Zope2, python scripts do not have __code__, they only have
func_code (and same for __defauls__/func_defaults).
We tried to backport the support of __code__ from Zope4 as a Zope2
patch - it was SlapOS patch 4fa33dfc6 (erp5: py3: `func_{code,defaults}`
was replaced in Python3 by `__{code,defaults}__`., 2022-04-25),
but this patch was incomplete. We tried to backport more, but then
realized that we don't need to use __code__ on ERP5 master yet,
because ERP5 master branch is still supporting Zope2 only.

This patch revert a small part of a17bb910 (py2/py3: Make Products
code compatible with both python2 and python3., 2022-04-13), the part
where we use f.__code__ where f might be a python script. For now,
we'll apply this patch only on the Zope4 branch.

A few places where f.func_code was used and f was a for sure not a
python script but a simple class method or function are kept here, as
__code__ support is missing only on in ZODB scripts.

product/ERP5/Document/Alarm.py

@@ -164,7 +164,7 @@ class Alarm(XMLObject, PeriodicityMixin):
           activate_kw['tag'] = '%s_%x' % (self.getRelativeUrl(), getrandbits(32))
         tag = activate_kw['tag']
         method = getattr(self, method_id)
-        func_code = method.__code__
+        func_code = method.func_code
         try:
           has_kw = func_code.co_flags & CO_VARKEYWORDS
         except AttributeError:

product/ERP5Type/Accessor/Accessor.py

@@ -41,7 +41,7 @@ class Accessor(Method):
     def __getinitargs__(self):
       init = getattr(self, '__init__', None)
       if init is not None:
-        varnames = init.__code__.co_varnames
+        varnames = init.func_code.co_varnames
         args = []
         for name in varnames:
           if name == 'self':

product/ERP5Type/Core/Predicate.py

@@ -181,7 +181,7 @@ class Predicate(XMLObject):
           try:
             result = method(self)
           except TypeError:
-            if method.__code__.co_argcount != isinstance(method, MethodType):
+            if method.func_code.co_argcount != isinstance(method, MethodType):
               raise
             # backward compatibilty with script that takes no argument
             warn('Predicate %s uses an old-style method (%s) that does not'

product/ERP5Type/Interactor/Interactor.py

@@ -71,8 +71,8 @@ class InteractorMethod(Method):
     self.after_action_list = []
     self.before_action_list = []
     self.method = method
-    self.__code__ = self.func_code = method.__code__
-    self.__defaults__ = self.func_defaults = method.__defaults__
+    self.func_code = method.func_code
+    self.func_defaults = method.func_defaults
     self.__name__ = method.__name__
 
   def registerBeforeAction(self, action, args, kw):

product/ERP5Type/Utils.py

@@ -234,7 +234,7 @@ def deprecated(message=''):
   @simple_decorator
   def _deprecated(wrapped):
     m = message or "Use of '%s' function (%s, line %s) is deprecated." % (
-      wrapped.__name__, wrapped.__module__, wrapped.__code__.co_firstlineno)
+      wrapped.__name__, wrapped.__module__, wrapped.func_code.co_firstlineno)
     def deprecated(*args, **kw):
       warnings.warn(m, DeprecationWarning, 2)
       return wrapped(*args, **kw)

product/ERP5Type/patches/OFSItem.py

@@ -44,7 +44,7 @@ def volatileCached(self, func):
     self._v_SimpleItem_Item_vCache = cache_dict = {}
   # Use whole func_code as a key, as it is the only reliable way to identify a
   # function.
-  key = func.__code__
+  key = func.func_code
   try:
     return cache_dict[key]
   except KeyError:

product/ZSQLCatalog/SQLCatalog.py

@@ -1452,7 +1452,7 @@ class Catalog(Folder,
     if meta_type in self.HAS_ARGUMENT_SRC_METATYPE_SET:
       return method.arguments_src.split()
     elif meta_type in self.HAS_FUNC_CODE_METATYPE_SET:
-      return method.__code__.co_varnames[:method.__code__.co_argcount]
+      return method.func_code.co_varnames[:method.func_code.co_argcount]
     # Note: Raising here would completely prevent indexation from working.
     # Instead, let the method actually fail when called, so _catalogObjectList
     # can log the error and carry on.
@@ -1838,7 +1838,7 @@ class Catalog(Folder,
       else:
         search_key = self.getSearchKey(key, 'RelatedKey')
     else:
-      func_code = script.__code__
+      func_code = script.func_code
       search_key = (
         AdvancedSearchKeyWrapperForScriptableKey if (
           # 5: search_value (under any name), "search_key", "group",