Clean up unused imports and variables

Removed unused AsyncGenerator import from nativeupload.py and cleaned up unused stdout variable in tests/conftest.py for better code clarity.

Author: JR-1991

dvuploader/nativeupload.py

@@ -4,7 +4,7 @@
 import tempfile
 from io import BytesIO
 from pathlib import Path
-from typing import IO, AsyncGenerator, Dict, List, Optional, Tuple
+from typing import IO, Dict, List, Optional, Tuple
 
 import httpx
 import rich

tests/conftest.py

@@ -159,9 +159,9 @@ def http_proxy_server():
         except TimeoutError:
             # Collect logs for debugging and skip the test instead of failing hard
             try:
-                stdout, stderr = proc.communicate(timeout=1)
+                _, stderr = proc.communicate(timeout=1)
             except Exception:
-                stdout, stderr = (b"", b"")
+                _, stderr = (b"", b"")
             msg = (
                 "Proxy did not start on "
                 f"{host}:{port}. stderr: {stderr.decode(errors='ignore').strip()}"