upgrade cadvisor to v0.42.0
Created by: ggilmore
See https://github.com/google/cadvisor/releases/tag/v0.42.0
address issue reported by https://buildkite.com/sourcegraph/sourcegraph/builds/112112#annotation-Docker%20image%20security%20scan
Created by: ggilmore
See https://github.com/google/cadvisor/releases/tag/v0.42.0
address issue reported by https://buildkite.com/sourcegraph/sourcegraph/builds/112112#annotation-Docker%20image%20security%20scan