Bump actions/upload-artifact from 4 to 6

Bumps [actions/upload-artifact](https://github.com/actions/upload-artifact) from 4 to 6.
- [Release notes](https://github.com/actions/upload-artifact/releases)
- [Commits](https://github.com/actions/upload-artifact/compare/v4...v6)

---
updated-dependencies:
- dependency-name: actions/upload-artifact
  dependency-version: '6'
  dependency-type: direct:production
  update-type: version-update:semver-major
...

Signed-off-by: dependabot[bot] <support@github.com>

.github/workflows/android-build-publish.yml

@@ -31,7 +31,7 @@ jobs:
         run: ./gradlew assembleDebug
 
       - name: Upload debug APK
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: app-debug.apk
           path: composeApp/build/outputs/apk/debug/composeApp-debug.apk
@@ -40,7 +40,7 @@ jobs:
         run: ./gradlew assembleRelease
 
       - name: Upload release APK
-        uses: actions/upload-artifact@v4
+        uses: actions/upload-artifact@v6
         with:
           name: app-release.apk
           path: composeApp/build/outputs/apk/release/composeApp-release.apk