Steps to reproduce the issue

• Install latest 4.2.0 beta 3
• Open front or admin

Expected result

Working pages :)

Actual result

 0 Operation timed out after 5007 milliseconds with 16384 out of 1204198 bytes received 

Additional comments

So I've traced this to plugins/system/webauthn/src/MetadataRepository.php:

$response = $http->get('https://mds.fidoalliance.org/', [], 5);

It times out after 5 seconds due to the 3rd param - my download speed is abysmal, not sure if related to my own internet or the hosting server...

Either way this shouldn't render the website unusable. Maybe catching the exception would be a temporary fix but this would still overload the URL, triggerring connections on every visit.
Can be fixed manually by downloading blob.jwt and renaming it to cache/fido.jwt and administrator/cache/fido.jwt