Revert "erp5: py3: `func_{code,defaults}` was replaced in Python3 by `__{code,defaults}__`."

This reverts commit 4fa33dfc.

This patch is not complete, backporting full support of
`__{code,defaults}__` on Zope2 would require patching more, so we
decided to keep using func_code with ERP5 on Zope2 and to use
__code__ only with ERP5 on Zope4

component/egg-patch/Zope/PythonScript-2.13.patch

---- Zope2-2.13.30/src/Shared/DC/Scripts/Signature.py	2022-04-25 08:05:09.312966168 +0000
-+++ Zope2-2.13.30/src/Shared/DC/Scripts/Signature.py	2022-04-25 08:06:20.120743425 +0000
-@@ -35,7 +35,7 @@ def _setFuncSignature(self, defaults=None, varnames=(), argcount=-1):
-         argcount = len(varnames)
-     # Generate a change only if we have to.
-     if self.func_defaults != defaults:
--        self.func_defaults = defaults
-+        self.func_defaults = self.__defaults__ = defaults
-     code = FuncCode(varnames, argcount)
-     if self.func_code != code:
--        self.func_code = code
-+        self.func_code = self.__code__ = code

stack/erp5/buildout.cfg

@@ -592,8 +592,6 @@ Acquisition-patches = ${:_profile_base_location_}/../../component/egg-patch/Acqu
 Acquisition-patch-options = -p1
 python-magic-patches = ${:_profile_base_location_}/../../component/egg-patch/python_magic/magic.patch#de0839bffac17801e39b60873a6c2068
 python-magic-patch-options = -p1
-Zope2-patches = ${:_profile_base_location_}/../../component/egg-patch/Zope/PythonScript-2.13.patch#124c0d37394dd5020c6fd241ad75cc29
-Zope2-patch-options = -p1
 
 [eggs-all-scripts]
 recipe = zc.recipe.egg
@@ -634,7 +632,6 @@ pysvn = 1.9.15+SlapOSPatched001
 python-ldap = 2.4.32+SlapOSPatched001
 python-magic = 0.4.12+SlapOSPatched001
 PyPDF2 = 1.26.0+SlapOSPatched001
-Zope2 = 2.13.30+SlapOSPatched001
 ## https://lab.nexedi.com/nexedi/slapos/merge_requests/648
 pylint = 1.4.4+SlapOSPatched002
 # astroid 1.4.1 breaks testDynamicClassGeneration