Blueman exception "AttributeError: 'ManagerDeviceMenu' object has no attribute 'SelectedDevice'" when disconnecting device

[Craig Ringer]

I installed blueman and used it to disconnect my Bluetooth audio headset (as it's incredibly annoying that GNOME insists on auto-connecting to it when I only want to use it on my mobile, but I don't want to have to unpair and re-pair every time).

When I double clicked on the headset in the blueman device list, the following exception was printed to the console:

```
$ /usr/bin/blueman-manager
Exception ignored on calling ctypes callback function: <bound method PulseAudioUtils.__list_callback of <PulseAudioUtils.PulseAudioUtils object at 0x7f22daa67e40 (blueman+main+PulseAudioUtils+PulseAudioUtils at 0x1607b40)>>
Traceback (most recent call last):
  File "/usr/lib/python3/dist-packages/blueman/main/PulseAudioUtils.py", line 240, in __list_callback
    info["handler"](entry_info, False)
  File "/usr/lib/python3/dist-packages/blueman/main/PulseAudioUtils.py", line 316, in handler
    callback(self.__card_info(entry_info))
  File "/usr/lib/python3/dist-packages/blueman/plugins/manager/PulseAudioProfile.py", line 55, in get_card_cb
    self.regenerate_with_device(card["proplist"]["device.string"])
  File "/usr/lib/python3/dist-packages/blueman/plugins/manager/PulseAudioProfile.py", line 42, in regenerate_with_device
    if inst.SelectedDevice['Address'] == device_addr and not inst.is_popup:
       ^^^^^^^^^^^^^^^^^^^
AttributeError: 'ManagerDeviceMenu' object has no attribute 'SelectedDevice'
```

Context:

```
$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description: Ubuntu 23.04
Release: 23.04
Codename: lunar
```

```
$ dpkg -l blueman pulseaudio-utils
||/ Name Version Architecture Description
+++-================-=====================-============-==================================================
ii blueman 2.3.5-2build1 amd64 Graphical bluetooth manager
ii pulseaudio-utils 1:16.1+dfsg1-2ubuntu3 amd64 Command line tools for the PulseAudio sound server
```

```
$ pip list --user
$
```