Migrate project to GitLab
This MR completes the migration process from github to gitlab by updating the project metadata and migrating the CI from github actions to gitlab-ci.
Maintenance will be performed on git.ligo.org, containers.ligo.org, and docs.ligo.org on Tuesday 9 July 2024 starting at approximately 9:30am PDT. It is expected to take around two hours and there will be several periods of downtime throughout the maintenance. Please address any comments, concerns, or questions to the helpdesk.
This MR completes the migration process from github to gitlab by updating the project metadata and migrating the CI from github actions to gitlab-ci.