Update T3 onboarding banner (#1907)

Author: osoriano

deploy-board/deploy_board/templates/deploys/warning_no_tier3.tmpl

@@ -1,12 +1,12 @@
 <div id="noTier3Alert" class="alert alert-danger" role="alert" align="center">
   <a href="#" class="close" data-dismiss="alert">&times;</a>
-  <i><b style="font-size:24px;">Tier 3 new service onboarding to Teletraan will be restricted starting Feb 9th, 2026.</b></i>
+  <i><b style="font-size:24px;">Tier 3 new service onboarding to Teletraan is now disabled.</b></i>
   <p>
      Please launch new Tier 3 services in PinCompute. PinCompute onboarding documentation may be found
      <a href="{{ pincompute_onboarding_link }}">here</a>.
      For any exceptions, please complete the
      <a href="{{ pincompute_exception_form_link }}">exception form</a>.
      For questions, please reach out to
-     <a href="{{ pincompute_slack_link }}">#cloud-runtime-k8s</a>.
+     <a href="{{ pincompute_slack_link }}">#pincompute</a>.
   </p>
 </div>