A classical race condition detected depending on host system CPU load while executing smoketests.
Removal of the Wireless/Wifi interfaces can cause a KeyError.
```
DEBUG -
DEBUG - Traceback (most recent call last):
DEBUG - File "/usr/libexec/vyos/conf_mode/interfaces_wireless.py", line 414, in <module>
DEBUG - apply(c)
DEBUG - File "/usr/libexec/vyos/conf_mode/interfaces_wireless.py", line 325, in apply
DEBUG - WiFiIf(**wifi).remove()
DEBUG - ^^^^^^^^^^^^^^
DEBUG - File "/usr/lib/python3/dist-packages/vyos/ifconfig/interface.py", line 358, in __init__
DEBUG - self._create()
DEBUG - File "/usr/lib/python3/dist-packages/vyos/ifconfig/wireless.py", line 33, in _create
DEBUG - cmd = ['iw', 'phy', self.config['physical_device'], 'interface', 'add',
DEBUG - ~~~~~~~~~~~^^^^^^^^^^^^^^^^^^^
DEBUG - KeyError: 'physical_device'
DEBUG -
DEBUG - noteworthy:
DEBUG - cmd 'ip link show dev wlan1'
DEBUG - returned (out):
DEBUG -
DEBUG - returned (err):
DEBUG - Device "wlan1" does not exist.
DEBUG -
DEBUG - delete [ interfaces wireless wlan1 ] failed
DEBUG - Commit failed
```
In `src/conf_mode/interfaces_wireless.py:apply()`, the delete path unconditionally does `WiFiIf(**wifi).remove()`.
Since the `wifi` dict for a deleted node never contains `physical_device`, and `Interface.__init__` calls `self._create()` whenever the kernel interface doesn't already exist, `WiFiIf._create()` crashes with `KeyError: 'physical_device'` when the interface never actually got created (or already vanished) before deletion.