Maybe interacted with CIs too much and it's Stockholm syndrome, but they are there to help tame and offload complexity, not just complexity for complexity'a sake
Theoretically. Practically, you're hunting for the reason why your GitHub token doesn't allow you to install a private package from another repository in your org during the build, then you learn you need a classic personal access token tied to an individual user account to interact with GitHub's own package registry, you decide that that sounds brittle and after some pondering, you figure that you can just create a GitHub app that you install in your org and write a small action that uses the GitHub API to create an on-demand token with the correct scopes, and you just need to bundle that so you can use it in your pipeline, but that requires a node_modules folder in your repository, and…
Oh! Could it be that you just added complexity for complexity's sake?
As long as you're pragmatic and honest with what you need from your CI setup, it's okay that it makes your system more complex—you're getting something in return after all.
Okay no but seriously, if you're not being held back by how slow GitHub CI/Gitlab runners are, great! For others they're slow as molasses and others in different languages with different build systems can run an iteration of their build REPL before git has even finished pushing, nevermind waiting for a runner.