slapos_upgrader: Don't include test specific upgrade script

   This is easily doable via portal_templates, so no need to keep ad-hoc scripts here.

master/bt5/slapos_upgrader/SkinTemplateItem/portal_skins/slapos_upgrader/ERP5Site_upgradeSlapOSTestUICoreBusinessTemplate.py

-template_tool = context.getPortalObject().portal_templates
-
-template_tool.updateRepositoryBusinessTemplateList(
-  template_tool.getRepositoryList())
-
-method_kw = {'bt5_list': ['erp5_ui_test_core', 'slapos_panel_ui_test', 'slapos_parameter_ui_test'],
-             'deprecated_after_script_dict': None,
-             'deprecated_reinstall_set': None,
-             'dry_run': False,
-             'delete_orphaned': False,
-             'keep_bt5_id_set': [],
-             'update_catalog': False}
-
-
-template_tool.upgradeSite(**method_kw)

master/bt5/slapos_upgrader/SkinTemplateItem/portal_skins/slapos_upgrader/ERP5Site_upgradeSlapOSTestUICoreBusinessTemplate.xml

-<?xml version="1.0"?>
-<ZopeData>
-  <record id="1" aka="AAAAAAAAAAE=">
-    <pickle>
-      <global name="PythonScript" module="Products.PythonScripts.PythonScript"/>
-    </pickle>
-    <pickle>
-      <dictionary>
-        <item>
-            <key> <string>_bind_names</string> </key>
-            <value>
-              <object>
-                <klass>
-                  <global name="_reconstructor" module="copy_reg"/>
-                </klass>
-                <tuple>
-                  <global name="NameAssignments" module="Shared.DC.Scripts.Bindings"/>
-                  <global name="object" module="__builtin__"/>
-                  <none/>
-                </tuple>
-                <state>
-                  <dictionary>
-                    <item>
-                        <key> <string>_asgns</string> </key>
-                        <value>
-                          <dictionary>
-                            <item>
-                                <key> <string>name_container</string> </key>
-                                <value> <string>container</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_context</string> </key>
-                                <value> <string>context</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_m_self</string> </key>
-                                <value> <string>script</string> </value>
-                            </item>
-                            <item>
-                                <key> <string>name_subpath</string> </key>
-                                <value> <string>traverse_subpath</string> </value>
-                            </item>
-                          </dictionary>
-                        </value>
-                    </item>
-                  </dictionary>
-                </state>
-              </object>
-            </value>
-        </item>
-        <item>
-            <key> <string>_params</string> </key>
-            <value> <string></string> </value>
-        </item>
-        <item>
-            <key> <string>id</string> </key>
-            <value> <string>ERP5Site_upgradeSlapOSTestUICoreBusinessTemplate</string> </value>
-        </item>
-      </dictionary>
-    </pickle>
-  </record>
-</ZopeData>