Tomcat like with every free service, you have limits. Tho im not sure but i recently uploaded my project, its small, but binaries are large, so idk.. I dont have paid gh account or anything.. freshly made account.
Thats why im telling you - self host ..
You could use gitlab?
In any case the defaults across all these git platforms are from 25mb - 100mb..
If you have something larger then seek other options..