[Feature flag] Remove feature flag for Datadog CI integration

What

Remove the :datadog_ci_integration feature flag

Owners

• Team: ~"group::ecosystem"
• Most appropriate slack channel to reach out to: #g_ecosystem
• Best individual to reach out to: @AdrianLC

Expectations

What are we expecting to happen?

All users and projects have now access to a new integration with Datadog

What might happen if this goes wrong?

Integration forms could fail or the list page for integrations could crash.

The integration will not work if the rollout is not coordinated with Datadog's rollout

What can we monitor to detect problems with this?

TODO

Beta groups/projects

If applicable, any groups/projects that are happy to have this feature turned on early. Some organizations may wish to test big changes they are interested in with a small subset of users ahead of time for example.

TODO

Roll Out Steps

• Enable on staging (/chatops run feature set datadog_ci_integration true --staging)
• Test on staging
• Ensure that documentation has been updated
• Enable on GitLab.com for individual groups/projects listed above and verify behaviour (/chatops run feature set --project=gitlab-org/gitlab datadog_ci_integration true)
• Coordinate a time to enable the flag with the SRE oncall and release managers
  • In #production by pinging @sre-oncall
  • In #g_delivery by pinging @release-managers
• Announce on the issue an estimated time this will be enabled on GitLab.com
• Enable on GitLab.com by running chatops command in #production (/chatops run feature set datadog_ci_integration true)
• Cross post chatops Slack command to #support_gitlab-com (more guidance when this is necessary in the dev docs) and in your team channel
• Announce on the issue that the flag has been enabled
• Remove feature flag and add changelog entry
• After the flag removal is deployed, clean up the feature flag by running chatops command in #production channel

Rollback Steps

• This feature can be disabled by running the following Chatops command:

/chatops run feature set --project=gitlab-org/gitlab datadog_ci_integration false