Strip of elements_enable_blik flag

[floriansuess-stripe]

Summary

Remove unused elements_enable_blik feature flag from test data and recorded network traffic files.

Motivation

The elements_enable_blik feature flag is no longer needed and was never actually used in the iOS SDK codebase. It only existed in test mock data and recorded network traffic files, but no Swift/Objective-C code ever referenced or checked this flag.

Since it's always set to true internally and provides no functional gating, removing it simplifies the test data without any impact on SDK functionality.

BLIK payment method support continues to work exactly as before - this flag was not part of the actual implementation.

Testing

• Validated JSON syntax remains correct in all modified files
• Confirmed zero references to elements_enable_blik remain in codebase
• Verified BLIK payment functionality is implemented independently of this flag
• All linting and formatting checks passed
• No functional tests affected since flag was unused in business logic

Changelog

No changelog entry needed - this is an internal cleanup of unused test data that doesn't affect external SDK behavior or APIs.