triage-policies: Change updated_at to created_at for unlabeled issues

So even if the bot does something, or there is some movement that are
not labels, the issue is still taken care of for proper triaging.

Increased also to two months to compensate for the change.

.triage-policies.yml

@@ -43,10 +43,10 @@ resource_rules:
       - name: Mark stale unlabelled issues for triage
         conditions:
           date:
-            attribute: updated_at
+            attribute: created_at
             condition: older_than
             interval_type: months
-            interval: 1
+            interval: 2
           # We want to handle those that doesn't have these labels, including those with other labels.
           forbidden_labels:
             - 1. Bug