chore: update itworks pipeline

Dockerfile

@@ -1,4 +1,4 @@
-FROM nginx:1.31.2-alpine
+FROM nginx:1.31.5-alpine
 
 RUN apk update && \
     apk upgrade --no-cache

index.html

@@ -39,7 +39,7 @@
   <div class="box">
     <h1>It works!</h1>
     <p>Pipeline git → build → push Harbor → sign cosign → deploy Portainer OK</p>
-    <div class="ts">2026-09-05 17:58:53 UTC</div>
+    <div class="ts">2026-09-05 18:01:03 UTC</div>
   </div>
 </body>
 </html>