Ignore test release environment names
What does this MR do and why?
Describe in detail what your merge request does and why.
Content
Release environment names doesn't have a rule, to let us create as many environments for testing as possible. Beside from that, there are environments for stable branches, which are created by release-tools.
This change adds a logic to ignore the non stable branch environments when searching for the latest environments, to avoid an error when the environment name cannot be converted to a branch name.
Besides, the spec is also updated to avoid duplications.
Edited by Dat Tang