Context:
People have been asking for IPv6 Support on GitHub since years (probably a decade by now)
... and someone even got so annoyed that they decided to setup a dedicated website for checking this: https://isgithubipv6.live/
The important bit is that almost every major web service is already running fully dual stacked. Azure, Amazon, Meta, CloudFlare, Google.... If it's a commonly known internet company, it's probably ready for IPv6.
There's still plenty that isn't ready, but most well known things have been ready for years at this point.