Arch Linux

Description:
Title says it all. After loads of recent python updates, ibus-anthy stops working. Indeed, Anthy is no longer visible in the IBUS preferences. When running ibus-daemon in console:
```
Traceback (most recent call last):
File "/usr/share/ibus-anthy/engine/main.py", line 44, in <module>
import factory
File "/usr/share/ibus-anthy/engine/factory.py", line 33, in <module>
import engine
File "/usr/share/ibus-anthy/engine/engine.py", line 59, in <module>
from anthyprefs import AnthyPrefs
ModuleNotFoundError: No module named 'anthyprefs'
```
On advice from Namarrgon in IRC, I rebuilt ibus-anthy, and sure enough, after restarting ibus-daemon, I was able to re-add the Anthy input method and now everything seems to work just fine.

Additional info:
* package version(s)
ibus 1.5.21-3
ibus-anthy 1.5.11-2
python 3.8.0-1
* config and/or log files etc.
N/A
* link to upstream bug report, if any
N/A

Steps to reproduce:
have IBUS set up to use ibus-anthy
pacman -Syu
restart X / restart ibus-daemon
no more Anthy input method in the IBUS preferences