Inactive projects are defined as follows:

Self-managed projects with any license (Free, Premium, or Ultimate) or
GitLab SaaS projects that have a Free license where the project meets
both of the following criteria:

1. The project repository size exceeds the size threshold defined in
the instance settings.
2. The project has not had any comments, commits, MRs, new issues, or
other activity for the length of time defined in the instance settings.