Jira issues list using the Jira project integration not displaying in GitLab 13.10

Summary

After upgrading to GitLab v13.10.0-ee, Jira issues list doesn't get populated anymore, with the component not being rendered at all (and no attempts to reach Jira)

Steps to reproduce

1. Install GitLab v13.10.0-ee
2. Create a new project, set the Jira integration (can use any URL, even without Jira itself)
3. Go to /project/path/-/integrations/jira/issues, and observe no attempt to render is being made (no error as well), except the top bar

What is the current bug behavior?

Jira issues are not being displayed.

What is the expected correct behavior?

The issues list should be rendered, and fetched from Jira.

Relevant logs and/or screenshots

Possible fixes

jira_issues_list is disabled by default in 13.10, and the jira_issues_integration FF removal in !52597 (merged) made the mount condition always return false, so the component is never rendered.

Reported by two Premium customers so far: 201310, 201319 (internal-only links)

/cc @hchouraria