Simplest tool to maintain local mirrors of git repos?

I want to have a local mirror/proxy for some repos I'm using.

The idea is having something I can point my reads to so that I'm free to migrate my upstream repositories whenever I want and also so that my stuff doesn't stop working if some of the jankiest third-party repos I use disappears.

I know the various forjego/gitea/gitlab/... (well, at least some of them - I didn't check the specifics) have pull mirroring, but I'm looking for something simpler... ideally something with a single config file where I list what to mirror and how often to update and which then allows anonymous read access over the network.

Does anything come to mind?