chore(ci): update Dockerfile

docker/debian/Dockerfile

-FROM rust:1-slim-buster
+FROM rust:1-slim-bullseye
 RUN apt-get update \
 	&& DEBIAN_FRONTEND=noninteractive apt-get -y install git build-essential \
 		dbus-x11 python3-dbusmock gettext lua5.3 lua-zlib \
@@ -23,3 +23,4 @@ RUN curl -O https://gitlab.alpinelinux.org/alpine/apk-tools/-/archive/v2.12.9/ap
 	&& make LUA=no LIBDIR=/usr/lib/x86_64-linux-gnu/ install \
 	&& cd .. \
 	&& rm -rf apk-tools-v2.12.9*
+RUN pip install python-dbusmock==0.28.4