MAINTAINERS: remove philips
MAINTAINERS: remove philips

I haven't been active in this project, so remove me.

Signed-off-by: Brandon Philips <766d97c0853d0742ad1f5c01d421baa45bb9b60e@redhat.com>

opencontainers/ocitools,opencontainers/runtime-tools,opencontainers/runtime-tools,opencontainers/ocitools