Update AppleWWDRCA certificate to G4

[soukicz]

Only the G4 certificate is valid for signing passes with certificates generated after the 27th of January, 2022 - https://pkpassvalidator.azurewebsites.net/

[tschoffelen]

Thanks for opening this PR, really appreciate your contribution!

This new root certificate might possibly not work with older pass certificates generated before that date, so if we release this, it would be a breaking version update (i.e. major version in semver).

Alternatively, should we encourage people to set their own WWDR certificate by better documenting the open setWwdrCertificatePath() and over time deprecating the default included certificate?

[razvanphp]

I can confirm that this is the right updated certificate for passes, not sure how it works for people on master since #119 was merged...

The old passes signed with the old certificate still work, it's just about NEW passes that needs to be signed with the new one, so we can upgrade the certificate at any time.

[tschoffelen]

Thanks for making this change!

[tschoffelen]

Released to Packagist as version 2.2.0