Clear POSTDISPLAY instead of unsetting #32

	on: [push, pull_request]
	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true
	env:
	IMAGE_CACHE_PATH: /tmp/.image-cache
	IMAGE_CACHE_NAME: zsh-autosuggestions-test
	jobs:
	determine-versions:
	runs-on: ubuntu-22.04
	outputs:
	versions: ${{ steps.set-versions.outputs.versions }}
	steps:
	- uses: actions/checkout@v3
	- id: set-versions
	run: \|
	echo "versions=$(
	grep "^[^#]" ZSH_VERSIONS \
	\| sed -E 's/(^\|$)/"/g' \
	\| paste -sd ',' - \
	\| sed -e 's/^/[/' -e 's/$/]/'
	)" >> $GITHUB_OUTPUT
	test:
	needs: determine-versions
	runs-on: ubuntu-22.04
	strategy:
	matrix:
	version: ${{ fromJson(needs.determine-versions.outputs.versions) }}
	steps:
	- uses: actions/checkout@v3
	- name: Docker image cache
	id: image-cache
	uses: actions/cache@v3
	with:
	path: ${{ env.IMAGE_CACHE_PATH }}
	key: image-cache-${{ matrix.version }}-${{ hashFiles('Dockerfile', 'install_test_zsh.sh', 'Gemfile.lock') }}
	- name: Load cached docker image if available
	if: ${{ steps.image-cache.outputs.cache-hit }}
	run: gunzip < $IMAGE_CACHE_PATH/$IMAGE_CACHE_NAME.tar.gz \| docker load
	- name: Build the docker image if necessary
	if: ${{ !steps.image-cache.outputs.cache-hit }}
	run: \|
	docker build --build-arg TEST_ZSH_VERSION=${{ matrix.version }} -t $IMAGE_CACHE_NAME .
	mkdir -p $IMAGE_CACHE_PATH
	docker save $IMAGE_CACHE_NAME \| gzip > $IMAGE_CACHE_PATH/$IMAGE_CACHE_NAME.tar.gz
	- name: Run the tests
	run: \|
	docker run --rm \
	-v $PWD:/zsh-autosuggestions \
	$IMAGE_CACHE_NAME \
	make test

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