Add cmake

Author: bording

Dockerfile.linux

@@ -1,6 +1,6 @@
 ARG ARCH='amd64'
 FROM multiarch/ubuntu-core:${ARCH}-focal
-RUN apt update && DEBIAN_FRONTEND=noninteractive apt -y install pkg-config
+RUN apt update && DEBIAN_FRONTEND=noninteractive apt -y install cmake pkg-config
 
 WORKDIR /nativebinaries
 COPY . /nativebinaries/