MAINTAINERS: Add K Prateek Nayak to scheduler reviewers

I've been fortunate to have K Prateek take an active interest in
my Proxy Execution patches. He's provided great review insights
and productive feedback, sometimes remembering the subtleties of
the patch series better than I do myself! And he has done all
this with great kindness and humility.

I've really appreciated his reviews, and I think everyone should
be so lucky, so I wanted to propose adding him to the scheduler
reviewers list.

Signed-off-by: John Stultz <jstultz@google.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Steven Rostedt (Google) <rostedt@goodmis.org>
Acked-by: K Prateek Nayak <kprateek.nayak@amd.com>
Acked-by: Juri Lelli <juri.lelli@redhat.com>
Acked-by: Vincent Guittot <vincent.guittot@linaro.org>
Acked-by: Dietmar Eggemann <dietmar.eggemann@arm.com>
Link: https://patch.msgid.link/20260325172615.2895622-1-jstultz@google.com