From Fedora Project Wiki
There are a variety of things to do to EOL a Fedora Release.
koji
Bodhi
PackageDB
Set the release to be End of Life in the PackageDB. Currently, that's done with the following db query:
update collection set statuscode = 9 where name = 'Fedora' and version = '11';
Announcement
FESCo announces the closure of the release to the package maintainers.