⚡ Bolt: Short-circuit Qobuz app secret validation

[davidjuarezdev]

💡 What: Modified _get_valid_secret in streamrip/client/qobuz.py to use asyncio.as_completed and cancel remaining background requests once a valid secret is found, instead of using asyncio.gather.
🎯 Why: To prevent "tail latency". When testing multiple secrets, asyncio.gather waits for all requests to finish (even invalid ones that might be slow or timeout) before returning the valid secret. Using as_completed allows us to short-circuit the execution and return the fast, valid response immediately.
📊 Impact: Speeds up the Qobuz login and secret-fetching phase. Instead of being blocked by the slowest invalid request (potentially taking several seconds), it now completes as fast as the quickest valid response.
🔬 Measurement: Verify by executing PYTHONPATH=. poetry run pytest tests/test_qobuz_client.py and noting the faster execution time for login tasks, as well as observing the clean termination of the asyncio loop without background leaks.

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PR created automatically by Jules for task 4619569938749258132 started by @davidjuarezdev