Improve expiration date scanning

[davidme-stripe]

Summary

Due to improvements in iOS' OCR and changes to modern cards, we're often seeing strings like Valid Thru 01/30 Security Code 123, which are not parsed by the existing logic. To catch these, we'll add another check to look for dates in a "00/00" format.

Before: 5/14 test cards successfully populated an expiration date on scan
After: 14/14 test cards succeeded. Scanning was marginally faster, as we don't have to wait for the timeout

Motivation

https://jira.corp.stripe.com/browse/MOBILESDK-3369

Testing

Tested on iPhone 16 Pro, iOS 18.3.2

Changelog

Adding

[github-actions]

🚨 New dead code detected in this PR:

STPCardScanner.swift:362 warning: Function 'handlePossibleExpirationDate(_:)' is unused

Please remove the dead code before merging.

If this is intentional, you can bypass this check by adding the label skip dead code check to this PR.

ℹ️ If this comment appears to be left in error, double check that the flagged code is actually used and/or make sure your branch is up-to-date with master.

[github-actions]

⚠️ Public API changes detected:

StripePaymentSheet

- public var link: StripePaymentSheet.PaymentSheet.LinkConfiguration
- }
- public struct LinkConfiguration {
- public var display: StripePaymentSheet.PaymentSheet.LinkConfiguration.Display
- public enum Display : Swift.String {
- case automatic
- case never
- public init?(rawValue: Swift.String)
- public typealias RawValue = Swift.String
- public var rawValue: Swift.String {
- get
- }
- }
- public init(display: StripePaymentSheet.PaymentSheet.LinkConfiguration.Display = .automatic)

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• Do these APIs need to be public or can they be protected with @_spi(STP)?
• If these APIs need to be public, assess whether they require an API review.

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• Does this require a breaking version change?
• Do these changes require API review?

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