fix(tests): use asyncio.run() instead of get_event_loop() in amazon test helper

get_event_loop() raises RuntimeError on Python 3.11+ Linux when no loop
exists. asyncio.run() creates its own loop per call — no deprecation warning,
works across all supported Python versions.

tests/tools/test_amazon_download_client.py

@@ -39,7 +39,7 @@ from core.download_plugins.types import AlbumResult, DownloadStatus, TrackResult
 # ---------------------------------------------------------------------------
 
 def run(coro):
-    return asyncio.get_event_loop().run_until_complete(coro)
+    return asyncio.run(coro)
 
 
 def _stream_info(