v-m/scrape: Increase timeout for k8s job

Scraping metrics from the Kubernetes API server has started taking 20+
seconds recondly.  Until I figure out the underlying cause, I'm
increasing the scrape timeout so that the _vmagent_ doesn't give up and
report the API server as "down."

victoria-metrics/scrape.yml

@@ -176,6 +176,7 @@ scrape_configs:
     - jenkins.pyrocufflink.blue
 
 - job_name: kubernetes
+  scrape_timeout: 30s
   scheme: https
   tls_config:
     ca_file: /run/secrets/kubernetes.io/serviceaccount/ca.crt