[SPARK-52055][PYTHON][CONNECT] Suppress the exception in ExecutePlanResponseReattachableIterator.__del__

### What changes were proposed in this pull request?

This PR proposes to suppress the exception in `ExecutePlanResponseReattachableIterator.__del__`.

### Why are the changes needed?

It tries its best effort to close it. When it fails, we should just ignore it.

Now when you run `./bin/pyspark --remote local` and `exit(0)` directly without doing anything, it shows a warning as below:

```
Exception ignored in: <function ExecutePlanResponseReattachableIterator.__del__ at 0x12229f7e0>
Traceback (most recent call last):
  File "/.../python/pyspark/sql/connect/client/reattach.py", line 347, in __del__
    return self.close()
           ^^^^^^^^^^^^
  File "/.../python/pyspark/sql/connect/client/reattach.py", line 343, in close
    self._release_all()
  File "/.../python/pyspark/sql/connect/client/reattach.py", line 245, in _release_all
    thread_pool.submit(target)
  File "/opt/miniconda3/envs/python3.11/lib/python3.11/concurrent/futures/thread.py", line 169, in submit
    raise RuntimeError('cannot schedule new futures after '
RuntimeError: cannot schedule new futures after interpreter shutdown
```

### Does this PR introduce _any_ user-facing change?

The warning will not be shown.

### How was this patch tested?

Manually via `./bin/pyspark --remote local`.

### Was this patch authored or co-authored using generative AI tooling?

No.

Closes apache#50847 from HyukjinKwon/SPARK-52055.

Authored-by: Hyukjin Kwon <[email protected]>
Signed-off-by: Dongjoon Hyun <[email protected]>

Author: HyukjinKwon

python/pyspark/sql/connect/client/reattach.py

@@ -344,4 +344,7 @@ def close(self) -> None:
         return super().close()
 
     def __del__(self) -> None:
-        return self.close()
+        try:
+            return self.close()
+        except Exception:
+            pass