fix: use stable Swift 6.2 release for guaranteed LLVM v9

The 6.2 nightly snapshots (August 28) might still have newer LLVM v10.
Using the stable 6.2 release (from September 2024) guarantees LLVM v9
compatibility with the Android SDK's profraw format.

🤖 Generated with [Claude Code](https://claude.com/claude-code)

Co-Authored-By: Claude Sonnet 4.5 <[email protected]>

Author: leogdion

.github/workflows/MistKit.yml

@@ -163,7 +163,7 @@ jobs:
       - name: Build and Test on Android
         uses: ./.github/actions/swift-android-action
         with:
-          swift-version: "nightly-6.2"  # Use latest 6.2 nightly for LLVM v9 compatibility
+          swift-version: "6.2"  # Use stable 6.2 release for LLVM v9 compatibility
           android-api-level: 34
           build-package: true
           build-tests: true