add missing dependency to base Docker image
add missing dependency to base Docker image

Missing libxkbcommon-x11-0 package lead to the error while loading xvfb
(no libxkbcommon-x11.so.0 library). This commit should fix CI builds.

DiCarloLab-Delft/PycQED_py3,DiCarloLab-Delft/PycQED_py3,DiCarloLab-Delft/PycQED_py3