Lighthouse v1.6.5 treats localhost/1.2.7.0.0.1 as secure domains (i.e. as if they where HTTPS), so we need to stop handling the is-on-https audit specially.
In some cases (unclear when), traceviewer-js, used by Lighthouse under the hood,
assumes `atob`/`btoa` are defined in the global scope. This is true for browser
environments, but not on node.
As a result, some aggregations that required access to model-tracing failed to
produce results, dropping the overall PWA score.
This affected #16665 (e.g. commit 0de6eec7a).