[PT-D] Update CODEOWNERS, merge_rules, and Persons-of-Interest for to… (#96321)
Synchronize CODEOWNERS, merge_rules, and POI files to reflect kiukchung and d4l3k (Tristan Rice) as one of the maintainers for the distributed module.
Pull Request resolved: https://github.com/pytorch/pytorch/pull/96321
Approved by: https://github.com/d4l3k, https://github.com/albanD, https://github.com/malfet
