It's so confusing,
https://github.com/ktorio/ktor/tree/2.3.8 there is a branch called 2.3.8 but no tag or release.
For 2.3.7 both a tag and a branch exist, but the GitHub Website would use the same url for both the tag and the branch so it only displays the commit history or file view for one of the two. (At least those seem to be on the same commit sha, but I have seen a case where tag and branch were on a different commit sha.)