We were previously testing the webkit engine on Linux, which however relies on a
different WebCrypto API implementation compared to the macOS version (behind Safari).
Also, increase mocha timeouts, as the argon2 memory-heavy test takes longer in Firefox.
To have tests work Browserstack Safari (also below iOS 15), as the tests are run in an iframe,
rewriting localhost as hostname, making WebCrypto not available.
We keep HTTP for the non-browserstack tests so that in local testing,
generating self-signed certs is not required.
