This is why I keep encouraging folks to a) have a mirror & b) make sure their tools automatically pick up the mirrors.
I recently got mirror support upstreamed into Nixpkgs for fetchdarcs & fetchpijul which actually work on my just-alpha-released pinning tool, Nixtamal <https://darcs.toastal.in.th/nixtamal/trunk/README.rst>, for just this sort of thing.
That's great for the repository, but what about if you're using ghcr, actions, issues, or copilot?
I envy you. Most of us struggle to get the resources to make our actual customer facing applications resilient, let alone our build pipeline.