Make non-top-level connection errors debug level

This avoids spamming the home-assistant logs, which can occur when
home-assistant has been running but the roomba hasn't been turned on, so
no initial connection has been established.
This allows users to read the logs/investigate other home-assistant
issues, without having to disable the roomba integration.

For example instead of this message being repeated 3x:

```
2024-MM-DD HH:MM:SS.MMM ERROR (roombapy) [roombapy.remote_client] Can't connect to 192.168.0.123
Traceback (most recent call last):
  File .../lib/python3.12/site-packages/roombapy/remote_client.py", line 93, in connect
    self._open_mqtt_connection()
  File .../lib/python3.12/site-packages/roombapy/remote_client.py", line 117, in _open_mqtt_connection
    self.mqtt_client.connect(self.address, self.port)
  File .../lib/python3.12/site-packages/paho/mqtt/client.py", line 914, in connect
    return self.reconnect()
           ^^^^^^^^^^^^^^^^
  File .../lib/python3.12/site-packages/paho/mqtt/client.py", line 1044, in reconnect
    sock = self._create_socket_connection()
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File .../lib/python3.12/site-packages/paho/mqtt/client.py", line 3685, in _create_socket_connection
    return socket.create_connection(addr, timeout=self._connect_timeout, source_address=source)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File .../lib/python3.12/socket.py", line 865, in create_connection
    raise exceptions[0]
  File .../lib/python3.12/socket.py", line 850, in create_connection
    sock.connect(sa)
OSError: [Errno 113] No route to host
```

and these then following:

```
2024-MM-DD HH:MM:SS.MMM ERROR (roombapy) [roombapy.remote_client] Unable to connect to 192.168.0.123
2024-MM-DD HH:MM:SS.MMM WARNING (roombapy) [roombapy.roomba] Unexpectedly disconnected from Roomba 192.168.0.123, code The connection was lost
2024-MM-DD HH:MM:SS.MMM WARNING (roombapy) [roombapy.roomba] Periodic connection lost due to Unable to connect to Roomba at 192.168.0.123
```

we now receive:
```
2024-MM-DD HH:MM:SS.MMM WARNING (roombapy) [roombapy.roomba] Unexpectedly disconnected from Roomba 192.168.0.123, code The connection was lost
```

With the ability to get back more detailed connection logs by enabling debug logging in home-assistant.

roombapy/remote_client.py

@@ -92,12 +92,12 @@ def connect(self) -> bool:
             try:
                 self._open_mqtt_connection()
             except Exception:
-                self.log.exception("Can't connect to %s", self.address)
+                self.log.debug("Can't connect to %s", self.address)
             else:
                 return True
             attempt += 1
 
-        self.log.error("Unable to connect to %s", self.address)
+        self.log.debug("Unable to connect to %s", self.address)
         return False
 
     def disconnect(self) -> None:

roombapy/roomba.py

@@ -165,7 +165,7 @@ def periodic_connection(self) -> None:
             except RoombaConnectionError as error:
                 self.periodic_connection_running = False
                 self.on_disconnect(MQTT_ERROR_MESSAGES[7])
-                self.log.warning("Periodic connection lost due to %s", error)
+                self.log.debug("Periodic connection lost due to %s", error)
                 return
             time.sleep(self.delay)