[CI] Update timeout for serverless pipeline (#12998)

Increased pipeline set in Serverless pipeline up to 6 hours.

Author: mrodm

.buildkite/pipeline.serverless.yml

@@ -60,7 +60,7 @@ steps:
   - label: "Check integrations in serverless"
     key: "test-integrations-serverless-project"
     command: ".buildkite/scripts/test_integrations_with_serverless.sh"
-    timeout_in_minutes: 240
+    timeout_in_minutes: 360
     env:
       FORCE_CHECK_ALL: true
       UPLOAD_SAFE_LOGS: 1