Replace a sensor which has been removed

[patriiiiiiiiiick]

Description

Steps to Reproduce

1. Have a BT device configured
2. Remove the underlying TRV/sensor
3. Edit the BT device to point to an existing TRV/sensor.
4. An error had occurred

Versions

HA 2023.12.0 BT 1.4.0

log

Logger: aiohttp.server
Source: /usr/local/lib/python3.11/site-packages/aiohttp/web_protocol.py:421
First occurred: 23:08:56 (1 occurrences)
Last logged: 23:08:56

Error handling request
Traceback (most recent call last):
  File "/usr/local/lib/python3.11/site-packages/aiohttp/web_protocol.py", line 452, in _handle_request
    resp = await request_handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/aiohttp/web_app.py", line 543, in _handle
    resp = await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/local/lib/python3.11/site-packages/aiohttp/web_middlewares.py", line 114, in impl
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/security_filter.py", line 85, in security_filter_middleware
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/forwarded.py", line 100, in forwarded_middleware
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/request_context.py", line 28, in request_context_middleware
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/ban.py", line 80, in ban_middleware
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/auth.py", line 233, in auth_middleware
    return await handler(request)
           ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/headers.py", line 31, in headers_middleware
    response = await handler(request)
               ^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/view.py", line 149, in handle
    result = await handler(request, **request.match_info)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/decorators.py", line 63, in with_admin
    return await func(self, request, *args, **kwargs)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/config/config_entries.py", line 234, in post
    return await super().post(request, flow_id)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/components/http/data_validator.py", line 72, in wrapper
    result = await method(view, request, data, *args, **kwargs)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/helpers/data_entry_flow.py", line 110, in post
    result = await self._flow_mgr.async_configure(flow_id, data)
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 293, in async_configure
    result = await self._async_handle_step(
             ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/usr/src/homeassistant/homeassistant/data_entry_flow.py", line 389, in _async_handle_step
    result: FlowResult = await getattr(flow, method)(user_input)
                         ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/config/custom_components/better_thermostat/config_flow.py", line 564, in async_step_user
    return await self.async_step_advanced(
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/config/custom_components/better_thermostat/config_flow.py", line 476, in async_step_advanced
    if HVACMode.AUTO in trv.attributes.get("hvac_modes"):
                        ^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'attributes'