data in transit
Yes, but then it is stored unencrypted on github. Ready to be used as training data by github.com/ Microsoft or whoever. Which isn't bad per se for i. e. public repositories. Just pointing out, that the weakest link in your chain of security measures is the... weakest link.
If you wanted to secure your code, you could store it on-site, behind a firewall, in its own network segment, with encrypted offsite backups. Elliptic curve cypto would help too in this scenario. And MFA. And access restrictions. Many possible measures.