fix: sort monthly release info by latest created time instead of version

Related to: gitlab-com/gl-infra/delivery#20022 (closed)

Snapshot (24 hrs): https://dashboards.gitlab.net/dashboard/snapshot/RsqfWwPylZEei7QRuTa3QLxDvxd76G7U

./test-dashboard.sh delivery/release_info.dashboard.jsonnet
Installed https://dashboards.gitlab.net/dashboard/snapshot/RsqfWwPylZEei7QRuTa3QLxDvxd76G7U - delivery: Release Information

There is a bug with how we displayed the metric on the dashboard because it was doing sorting by value, which only sorts by alphanumerical string (and does not support semver). It would calculate that 16.10 < 16.11 < 16.9, and show an incorrectly calculated value when we want to display the value for the latest version (16.11).

As a workaround, this change sorts by the latest time a metric is created by first calculating the min (first) time the grouped metric was created, then sorting by the highest Time (min).