Make logger shared state concurrency-safe

[kieran-osgood-shopify]

What changes are you making?

How to test

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Before you merge

Important

• I've added tests to support my implementation
• I have read and agree with the Contribution Guidelines
• I have read and agree with the Code of Conduct
• I've updated the relevant platform README (platforms/swift/README.md and/or platforms/android/README.md)

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Releasing a new Swift version?

• I have bumped the version in platforms/swift/ShopifyCheckoutKit.podspec
• I have bumped the version in platforms/swift/Sources/ShopifyCheckoutKit/ShopifyCheckoutKit.swift
• I have updated platforms/swift/CHANGELOG.md
• I have updated the SwiftPM/CocoaPods version snippets in platforms/swift/README.md (major version only)

Releasing a new Android version?

• I have bumped the versionName in platforms/android/lib/build.gradle
• I have updated platforms/android/CHANGELOG.md
• I have updated the Gradle/Maven version snippets in platforms/android/README.md

Tip

See the Contributing documentation for the full release process per platform.

[kieran-osgood-shopify]

Warning

This pull request is not mergeable via GitHub because a downstack PR is open. Once all requirements are satisfied, merge this PR as a stack on Graphite.
Learn more

• Apply SwiftFormat cleanup for Swift 6 stack #98 : 2 dependent PRs (#97 , #99 )
• feat: swift 6 language mode #92
• Fix Swift 6 test target isolation #91
• Align PassKit protocol abstractions with Swift 6 #90
• Isolate wallet controllers to the main actor #89
• Make Storefront cache and GraphQL values Sendable #88
• Make generated JSON coding key Sendable #87
• Make logger shared state concurrency-safe #86 👈 (View in Graphite)
• Make CheckoutKit configuration configure-only #85
• Mark CheckoutKit UI as main actor isolated #84
• main

This stack of pull requests is managed by Graphite. Learn more about stacking.