build(deps): bump backend to 0.1.68-anki26.05

[david-allison]

• Lint is failing due to not understanding use {
• Blocked by dependency Currently blocked by some other dependent / related change
  • build(deps): bump kotlin from 2.3.21 to 2.4.20 #21813 + Dependency updates 20260903 #21710
  • Dependency updates 20260903 #21710 - Kotlin needed to be undone
  • Backend release: https://github.com/ankidroid/Anki-Android-Backend/actions/runs/34763498015

Purpose / Description

The primary purpose of the backend bump is to add strongly-typed database exceptions, so we can remove an android dependency now, rather than waiting for this to become a breaking change in future refactors.

• ankidroid/Anki-Android-Backend@cb252e0

I will not include this exception-related code in this PR. The bolded change is a CI fix, and is more important for development velocity.

Primarily: a4a513375f2ac8c1da8ec871209ce6542b861065

• adds strongly typed backend exceptions so Anki-Android can move to these before removing an android SQLite dependency (when we move the backend to java-library)
• Fixes use-after-free bug causing macOS test failures
• removes Backend.checkOperationsRunOnMainThread
• dependencies:
  • protobuf-kotlin-lite 4.36.1
  • slf4j-api 1.7.36
    • replacing Timber
  • androidx.sqlite 2.7.0
  • risky Rust/JNI bump

Fixes

• Fixes macOS CI: non-zero exit value 134 #21455
• Part of Convert rsdroid[-testing] to a java-library Anki-Android-Backend#674

How Has This Been Tested?

Trusting unit tests & CI for this one. The change itself should be non-functional.

Learning (optional, can help others)

• build: bump version to 0.1.67-anki26.05 Anki-Android-Backend#736
• build: bump version to 0.1.68-anki26.05 Anki-Android-Backend#738
• ankidroid/Anki-Android-Backend@307254b...fc23f69

Checklist

• You have a descriptive commit message with a short title (first line, max 50 chars).
• You have commented your code, particularly in hard-to-understand areas
• You have performed a self-review of your own code
• UI changes: include screenshots of all affected screens (in particular showing any new or changed strings)
• UI Changes: You have tested your change using the Google Accessibility Scanner

[david-allison]

Hmm... those lint checks should be fixed, I'll take them on in main