This exact same question was posed to me before if I can just find my answer to it somewhere.
TLDR: eat the same way you’ve been eating or even a bit more this week to get the most recovery/fatigue management benefit out of your deload week.
Yoga was suggested and I think it could be a good idea just to stay mobile and promote stress relief + relaxation but excessive stretching and mobility work probably isn’t a good idea if you don’t usually do it or if it’s beyond the requirements of your sport or goals.