$ LANGUAGE=en sudo apt-get remove lxd --purge
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package 'lxd' is not installed, so not removed
The following packages were automatically installed and are no longer required:
  ebtables fcitx-libs fcitx-libs-gclient fcitx-libs-qt freetds-common
  gdb-multiarch libmysqlclient18 libodbc1 libsybdb5 libxcb-xinerama0
  lxd-client mysql-common
Use 'apt-get autoremove' to remove them.
0 upgraded, 0 newly installed, 0 to remove and 9 not upgraded.

$ ll /etc/default/lxd-bridge
-rw-r--r-- 1 root root 261 janv.  1 12:46 /etc/default/lxd-bridge