[FR]: Keep versions ordered in versions.bzl

[jklukas]

What is the current behavior?

The script for pulling in new releases to versions.bzl always includes the new version at the top of the list.

Describe the feature

Update the script to keep versions in descending order for easier understanding at a glance about which are included.

[jklukas]

I had assumed the list was ordered, which led me to submit #87 which wasn't necessary.

[alexeagle]

We can just ask Buildifier to do this with a # keep-sorted comment 😇