[Python] Fix DeviceProxyWrapper __del__ (project-chip#34011)

During tests the following unrelated Exception was raised:
```
Exception ignored in: <function DeviceProxyWrapper.__del__ at 0x7f12177b7a60>
Traceback (most recent call last):
  File "/__w/connectedhomeip/connectedhomeip/out/venv/lib/python3.9/site-packages/chip/ChipDeviceCtrl.py", line 306, in __del__
    if (self._proxyType == self.DeviceProxyType.OPERATIONAL and self.self._dmLib is not None and hasattr(builtins, 'chipStack') and builtins.chipStack is not None):
AttributeError: 'DeviceProxyWrapper' object has no attribute 'self'
Exception ignored in: <function DeviceProxyWrapper.__del__ at 0x7f12177b7a60>
Traceback (most recent call last):
  File "/__w/connectedhomeip/connectedhomeip/out/venv/lib/python3.9/site-packages/chip/ChipDeviceCtrl.py", line 306, in __del__
    if (self._proxyType == self.DeviceProxyType.OPERATIONAL and self.self._dmLib is not None and hasattr(builtins, 'chipStack') and builtins.chipStack is not None):
AttributeError: 'DeviceProxyWrapper' object has no attribute 'self'
```

This fixes the issue by removing the extra `self` in the condition.

Author: agners

src/controller/python/chip/ChipDeviceCtrl.py

@@ -268,7 +268,7 @@ def __init__(self, deviceProxy: ctypes.c_void_p, proxyType, dmLib=None):
 
     def __del__(self):
         # Commissionee device proxies are owned by the DeviceCommissioner. See #33031
-        if (self._proxyType == self.DeviceProxyType.OPERATIONAL and self.self._dmLib is not None and hasattr(builtins, 'chipStack') and builtins.chipStack is not None):
+        if (self._proxyType == self.DeviceProxyType.OPERATIONAL and self._dmLib is not None and hasattr(builtins, 'chipStack') and builtins.chipStack is not None):
             # This destructor is called from any threading context, including on the Matter threading context.
             # So, we cannot call chipStack.Call or chipStack.CallAsyncWithCompleteCallback which waits for the posted work to
             # actually be executed. Instead, we just post/schedule the work and move on.