Environments in stopping state are not shown on the environment index page and there's no way to stop them in UI

As a fix for Environments should not show as stopped if on_s... (#332301 - closed) we added a new stopping state to environments.

It however introduced a case when environment is not shown on the environments index page on any of available/stopped tab because it belongs to neither right now...

steps to reproduce

1. create a project with the following .gitlab-ci.yml:

deploy_job:
 script: "echo deploy1"
 environment:
   name: env_test_stop
   on_stop: stop_job
   action: start

stop_job:
  script: "stop1"
  when: manual
  environment:
    name: env_test_stop
    action: stop

2. wait for deploy job to finish, go to environments page and press stop button
3. see that environment is gone from both pages

Demo video: https://www.loom.com/share/9d1bc765d614407d93ffed4163450f75

Solution

• Rename the Available tab to Active (to capture more of the states within it).
• Place environments with the Stopping status in the Active tab.