Update actions/upload-artifact action to v6

Author: renovate[bot]

.github/workflows/android.yml

@@ -37,7 +37,7 @@ jobs:
       run: ./gradlew assembleDebug
 
     - name: Upload APK artifact
-      uses: actions/upload-artifact@v4
+      uses: actions/upload-artifact@v6
       with:
         name: app-debug
         path: app/build/outputs/apk/debug/app-debug.apk