chore: Bump version to 1.1.6-rc and add ARM64 workflow

- Update version to 1.1.6-rc for release candidate testing
- Add Linux ARM64/aarch64 build workflow
- Uses ubuntu-24.04-arm GitHub runner (free for public repos)
- Builds .deb, .rpm, .AppImage, and AUR tarball for ARM64
- Workflow isolated with continue-on-error to not block x86_64 builds

package.json

@@ -1,6 +1,6 @@
 {
   "name": "qbz-nix",
-  "version": "1.1.5",
+  "version": "1.1.6-rc",
   "description": "Native Qobuz client for Linux with Hi-Fi audio support",
   "type": "module",
   "scripts": {