tax_return: do not export this security

this demonstrate another potential problem of carelessly using path portal_type/X/** to export portal type configuration

bt5/erp5_tax_return/PathTemplateItem/portal_types/Sample%20Tax%20Return/12.xml

-<?xml version="1.0"?>
-<ZopeData>
-  <record id="1" aka="AAAAAAAAAAE=">
-    <pickle>
-      <global name="Role Information" module="erp5.portal_type"/>
-    </pickle>
-    <pickle>
-      <dictionary>
-        <item>
-            <key> <string>description</string> </key>
-            <value> <string>Configured by ERP5 Configurator</string> </value>
-        </item>
-        <item>
-            <key> <string>id</string> </key>
-            <value> <string>12</string> </value>
-        </item>
-        <item>
-            <key> <string>role_category</string> </key>
-            <value>
-              <tuple>
-                <string>function/unternehmen/mitarbeiter</string>
-              </tuple>
-            </value>
-        </item>
-        <item>
-            <key> <string>role_name</string> </key>
-            <value>
-              <tuple>
-                <string>Assignor</string>
-                <string>Assignee</string>
-                <string>Associate</string>
-                <string>Auditor</string>
-                <string>Author</string>
-              </tuple>
-            </value>
-        </item>
-        <item>
-            <key> <string>title</string> </key>
-            <value> <string>Default</string> </value>
-        </item>
-      </dictionary>
-    </pickle>
-  </record>
-</ZopeData>