fix(cloudformation): extend failure signal delay

Increase the failure signal delay to 20 minutes to give
bootstrap more time before CloudFormation marks it failed.

Co-authored-by: Cursor <cursoragent@cursor.com>

Author: pRizz

scripts/provisioning/opencode-cloud-setup-cloudformation.sh

@@ -50,8 +50,8 @@ signal_result() {
   fi
 
   if [ "$exit_code" -ne 0 ]; then
-    opencode_setup_log "opencode-cloud setup: delaying failure signal 300s (reason: $reason)"
-    sleep 300
+    opencode_setup_log "opencode-cloud setup: delaying failure signal 1200s (reason: $reason)"
+    sleep 1200
   fi
 
   opencode_setup_log "opencode-cloud setup: send cloudformation signal (reason: $reason)"