Build keyman core on linux via docker

Dockerfile

FROM --platform=amd64 ubuntu:latest

USER root
ENV HOME /home/build
ENV DEBIAN_FRONTEND noninteractive
RUN useradd -c "Build user" -d $HOME -m build
RUN apt-get -q -y update && apt-get -q -y upgrade
RUN apt-get -q -y install devscripts equivs
# TODO: assume that linux/debian/control was copied into the same directory
COPY control /tmp/control
RUN (yes | mk-build-deps --install /tmp/control) || true
RUN apt-get -q -y install meson
RUN apt-get -q -y install python3 python3-setuptools
VOLUME /home/build
WORKDIR /home/build
USER build

# To use:
# $ docker build -t keyman-linux-build .
# $ cd keyman/core
# $ mkdir -p build/linux
# $ docker run -it --rm -v $(pwd)/..:/home/build -v $(pwd)/build/linux:/home/build/core/build keyman-linux-builder:latest bash -c 'cd core; bash build.sh

see keymanapp/keyman#7102