Update documented availability exception time window to match GCP settings

Update downtime text (in file) (viewable at this link) to match current settings in google cloud.

Suggested text:

Your test/development environment will be generally available 24/7, with a 1-hour exception from 2 to 3 AM Central Time for software updates. Any known outages or issues at that time should be communicated to you by the Vetsource team.

Schedule was updated on or around June 11:

https://vetsource.slack.com/archives/C08KU4HRNQP/p1749668128706289