Import requests and HTTPAdapter in download_qnn_sdk.py

Added requests library and HTTPAdapter for improved HTTP handling.

Author: cccclai

backends/qualcomm/scripts/download_qnn_sdk.py

@@ -13,7 +13,8 @@
 import urllib.request
 import zipfile
 from typing import Dict, List, Optional, Tuple
-
+import requests
+from requests.adapters import HTTPAdapter, Retry
 
 logger = logging.getLogger(__name__)
 logger.addHandler(logging.NullHandler())