GitHub API proxy isn't working correctly

[kokrui]

Describe the bug

Right now we can visit https://github.nusmods.com/, but the relevant API proxies (/repo) and (/venues) aren't returning any data. https://github.com/nusmodifications/nusmods/pull/3655 was merged as a stopgap so that the contributor list can be shown, but we should restore the proxy soon and revert https://github.com/nusmodifications/nusmods/pull/3655