Update DNS to new infrastructure

[scovetta]

I'm migrating the existing metrics.openssf.org infrastructure over to a new VM in the OpenSSF Azure subscription. This means that it'll have a new IP address.

We'll need the CNAME for metrics.openssf.org changed:

From:
openssf-metricdb.westcentralus.cloudapp.azure.com

To:
openssf-metrics.westus3.cloudapp.azure.com

The new record should resolve metrics.openssf.org to 20.106.91.91.

If possible, we should try to make this change either early Tuesday evening or early Friday evening, to allow for testing - we'd like the new site to be live on Monday.