make `link_nvidia_host_libraries.sh` script a bit more robust, in case target of host_injections directory is a non-existing directory #1246

	# documentation: https://help.github.com/en/articles/workflow-syntax-for-github-actions
	name: Tests for init scripts
	on: [push, pull_request]
	permissions:
	contents: read # to fetch code (actions/checkout)
	jobs:
	build:
	runs-on: ubuntu-20.04
	strategy:
	matrix:
	python: [3.6, 3.7, 3.8, 3.9, '3.10']
	fail-fast: false
	steps:
	- name: checkout
	uses: actions/checkout@93ea575cb5d8a053eaa0ac8fa3b40d7e05a33cc8 # v3.1.0

	- name: set up Python
	uses: actions/setup-python@13ae5bb136fac2878aff31522b9efb785519f984 # v4.3.0
	with:
	python-version: ${{matrix.python}}
	architecture: x64

	- name: install Python packages
	run: \|
	pip install archspec pytest

	- name: unit tests for eessi_software_subdir_for_host.py script
	run:
	pytest -v init/test.py

	- name: test eessi_software_subdir_for_host.py script
	env:
	EESSI_X86_64: /tmp/EESSI/software/linux/x86_64
	run: \|
	mkdir -p ${EESSI_X86_64}/intel/{pentium4,sandybridge,haswell,skylake_avx512} ${EESSI_X86_64}/generic
	python3 ./init/eessi_software_subdir_for_host.py /tmp/EESSI > out.txt
	grep '^x86_64/' out.txt

	# check override via $EESSI_SOFTWARE_SUBDIR_OVERRIDE
	export EESSI_SOFTWARE_SUBDIR_OVERRIDE=x86_64/intel/pentium4
	python3 ./init/eessi_software_subdir_for_host.py /tmp/EESSI > out.txt
	grep '^x86_64/intel/pentium4$' out.txt

Provide feedback