Sub-path deploys, which is what you need for a project page served from
example.github.io/my-project/ rather than a domain root.
Getting a site to work under a base path is the kind of change that is only finished when every URL respects it. The graph's links were the ones still pointing at the root. Alongside that, GitLab Pages is now auto-detected, so its base path is inferred rather than configured by hand.
Dependabot started watching the dependency tree here.