Create a fedora 6.8 kernel with sched_ext
I rebased fedora-6.8 on top of https://github.com/sched-ext/sched_ext/tree/sched_ext-ci as cherry-picking commits wasn't an option (too many conflicts that needed to be resolved).
This goal here is to provide a packaged kernel that users can download/install and run/develop sched_ext schedulers on fedora.
I tested this branch by following the instructions here and installing it: https://docs.fedoraproject.org/en-US/quick-docs/kernel-build-custom/#_building_the_kernel
And running the schedulers from here: https://github.com/sched-ext/scx