chore: upgrade Harness to 1.5.0

[mrousavy]

Upgrade React Native Harness from 1.3.0 to 1.5.0, including the Android, Apple, and UI packages, Bun lockfile, and HarnessUI CocoaPod.

After reviewing the release notes and intervening changelog:

• Move SF Symbol tests to image-loaders.ios.harness.ts, using platform-specific discovery instead of a runtime platform guard and placeholder skipped test.
• Use context.skip() for unavailable HEIC capabilities so these tests report as skipped instead of passing without assertions.
• Ignore generated .harness/ caches and artifacts now that Metro caching is enabled by default.

The current config does not use deprecated Harness options. Keep allowHardware: false in screenshot tests: Harness's Android screenshot implementation still draws into a software canvas and is unchanged from 1.3.0.

Validation:

• Frozen Bun install, Biome, both package builds, and the example TypeScript check pass.
• Both runners load through the new harness ci load-config command.
• Test discovery finds seven shared suites on Android and those seven plus the SF Symbol suite on iOS.
• CocoaPods installation and the iOS simulator app build pass.
• Full iOS Harness suite passes on iPhone 17 Pro / iOS 26.2: 81 tests across 8 suites. Android execution is left to the existing PR workflow.