reuse existing image instead of manual toolchain install #4

	# This starter workflow is for a CMake project running on a single platform. There is a different starter workflow if you need cross-platform coverage.
	# See: https://github.com/actions/starter-workflows/blob/main/ci/cmake-multi-platform.yml
	name: CMake on a single platform

	on:
	push:
	branches: [ "master" ]
	pull_request:
	branches: [ "master" ]

	env:
	# Customize the CMake build type here (Release, Debug, RelWithDebInfo, etc.)
	BUILD_TYPE: Release

	jobs:
	build:
	# The CMake configure and build commands are platform agnostic and should work equally well on Windows or Mac.
	# You can convert this to a matrix build if you need cross-platform coverage.
	# See: https://docs.github.com/en/free-pro-team@latest/actions/learn-github-actions/managing-complex-workflows#using-a-build-matrix
	runs-on: ubuntu-latest
	container:
	image: ghcr.io/modm-ext/modm-build-cortex-m:2023-03-12

	steps:
	- name: Git checkout recursively
	uses: actions/checkout@v4
	with:
	submodules: 'recursive'

	- name: Configure CMake
	# Configure CMake in a 'build' subdirectory. `CMAKE_BUILD_TYPE` is only required if you are using a single-configuration generator such as make.
	# See https://cmake.org/cmake/help/latest/variable/CMAKE_BUILD_TYPE.html?highlight=cmake_build_type
	run: cmake -B ${{github.workspace}}/build -DCMAKE_BUILD_TYPE=${{env.BUILD_TYPE}}

	- name: Build
	# Build your program with the given configuration
	run: cmake --build ${{github.workspace}}/build --config ${{env.BUILD_TYPE}}

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