fix: resolve ruff lint violations in test files

- F841: unused `conn` variables in test_pool.py
- SIM105: try/except/pass replaced with contextlib.suppress
- F401: unused AsyncMock import in test_retry.py

Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>

Author: antoineleclair

tests/test_pool.py

@@ -1,5 +1,6 @@
 """Tests for connection pooling."""
 
+import contextlib
 from unittest.mock import AsyncMock, MagicMock, patch
 
 import pytest
@@ -104,18 +105,16 @@ async def test_cancellation_does_not_leak_connection(self) -> None:
         acquired = asyncio.Event()
 
         async def hold_connection():
-            async with pool.acquire() as conn:
+            async with pool.acquire() as _:
                 acquired.set()
                 await asyncio.sleep(10)  # Hold forever
 
         task = asyncio.create_task(hold_connection())
         await acquired.wait()  # Deterministic: wait until connection is acquired
 
         task.cancel()
-        try:
+        with contextlib.suppress(asyncio.CancelledError):
             await task
-        except asyncio.CancelledError:
-            pass
 
         # Connection should have been closed, size decremented
         mock_conn.close.assert_called()
@@ -188,7 +187,7 @@ async def test_close_handles_checked_out_connections(self) -> None:
 
         # Acquire a connection (checks it out)
         ctx = pool.acquire()
-        conn = await ctx.__aenter__()
+        await ctx.__aenter__()
 
         # Close the pool while connection is checked out
         await pool.close()

tests/test_retry.py

@@ -74,7 +74,7 @@ async def raise_type_error() -> str:
 
     async def test_respects_max_delay(self) -> None:
         """Verify that the backoff delay is capped at max_delay."""
-        from unittest.mock import AsyncMock, patch
+        from unittest.mock import patch
 
         call_count = 0
         sleep_args: list[float] = []