slapos_cloud: Use transactional data for ensure etags is consistent

   By using getModificationDate, it ensures that the data is set according to the transaction, since catalog can be updated since the transaction started leading to a recent etag using outdated cache from the transaction.

master/bt5/slapos_cloud/MixinTemplateItem/portal_components/mixin.erp5.SlapOSComputeNodeMixin.py

@@ -135,15 +135,17 @@ class SlapOSComputeNodeMixin(object):
     # check max indexation timestamp
     # it is unlikely to get an empty catalog
     last_indexed_entry = self.getPortalObject().portal_catalog(
-      select_list=['indexation_timestamp'],
+      select_list=['indexation_timestamp', 'modification_date'],
       portal_type=['Compute Node', 'Compute Partition',
                    'Software Instance', 'Slave Instance',
                    'Software Installation'],
       sort_on=[('indexation_timestamp', 'DESC')],
       limit=1,
     )[0]
-    return '%s_%s' % (last_indexed_entry.uid,
-                      last_indexed_entry.indexation_timestamp)
+    return '%s_%s_%s_%s' % (last_indexed_entry.uid,
+                      last_indexed_entry.indexation_timestamp,
+                      last_indexed_entry.modification_date,
+                      last_indexed_entry.getModificationDate())
 
   def _isTestRun(self):
     if self.REQUEST.get('disable_isTestRun', False):