chore(deps): bump third_party/cmp from `643e6a6` to `9b8fa1e` #5803

Job	Run time
docker-toxcore-js	1m 57s
docker-windows-mingw (32)	6m 47s
docker-fuzzer	11s
docker-esp32	2m 42s
docker-bootstrap-node	58s
docker-clusterfuzz	1m 21s
docker-windows-mingw (64)	6m 29s
docker-bootstrap-node-websocket	18s
	20m 43s

Provide feedback