sched_ext: Merge branch 'for-6.17-fixes' into for-6.18

Pull sched_ext/for-6.17-fixes to receive:

 55ed11b1 ("sched_ext: idle: Handle migration-disabled tasks in BPF code")

which conflicts with the following commit in for-6.18:

 2407bae2 ("sched_ext: Add the @sch parameter to ext_idle helpers")

The conflict is a simple context conflict which can be resolved by taking
the updated parts from both commits.

Signed-off-by: Tejun Heo <tj@kernel.org>