CI: find way to test SubtleCrypto in iOS Safari 15+ (secure context)

[larabr]

iOS Safari 15+ on Browserstack does not expose crypto.subtle since it does not recognise the (remote) localhost environment as having secure context.

For now, we can fallback to testing on iOS 14, and test iOS 15+ manually through Browserstack Live (through self-signed certificate). But we should find a way to test later versions .
Tried without success:

• set up self-signed certificate in the Workflow, then have karma connect to https://bs-local.com on Browserstack. Problem: Safari prompts to trust the certificate, despite passing the options proxyValidateSSL (for Karma) and acceptInsecureCerts/acceptSslCerts (for BS capabilities), so the tests hang before even starting.

Possible solutions:

• upload test bundle to Github Pages (which have valid HTTPS cert) then have Browserstack connect to the live URL.
• keep an eye on: Secure context support in Safari 15+ fingerprintjs/broyster#36