Updates Stripe SDK to 24.21.0 and adds CryptoOnramp

[Twigz]

Summary

• Updates Stripe iOS SDK to 24.21.0
• Adds CryptoOnramp as a dependency.

Motivation

This update includes work done for adding CryptoOnramp to the platform.

Testing

yarn run test passes, and the example compiles.
Made sure importing StripeCryptoOnramp worked, and that files referenced in that framework were accessible.

Documentation

Select one:

• I have added relevant documentation for my changes.
• This PR does not result in any developer-facing changes.