Download links no longer work, presumably due to expired artifacts

For example, clicking `windows-editor` on https://godotengine.github.io/godot-commit-artifacts/'s `master` branch (which tries to download `https://godotengine.github.io/godot-commit-artifacts/download/godotengine/godot/master/windows-editor`) results in a GitHub 404 page, even though I'm logged in.

Interestingly, if you open any GitHub page just after getting this 404 error, this shows up at the top of the page:

It seems CI hasn't run since August 2025, which likely explains why links aren't working anymore (since artifacts have expired). Maybe we should also switch links to use https://nightly.link/, so that they work without a login.