docker/coreboot-jenkins-node: Add meson and ninja

Our jenkins instance is also used for flashrom, which can be built with
meson, a mode that we want to be able to test, so add that.

ninja can be used as a backend to both meson and cmake (which coreboot
will use to build cmocka for its unit tests) and may provide some
additional coverage. Plus it's tiny but fast.

Change-Id: If454164852303144eaa72c4071c03ee89e863318
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41731
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

util/docker/coreboot-jenkins-node/Dockerfile

@@ -19,6 +19,7 @@ USER root
 
 RUN apt-get -y update && \
 	apt-get -y install \
+	meson ninja-build \
 	lua5.3 liblua5.3-dev default-jre-headless openssh-server && \
 	apt-get clean