Bump actions/checkout to remove warning deprecation #260

	---
	# Check commits and incoming PRs that change anything under ci/.
	name: Check CI

	'on':
	push:
	paths:
	- 'ci/**'
	pull_request:
	paths:
	- 'ci/**'
	types:
	- opened
	- reopened
	- edited
	- ready_for_review
	- synchronize

	permissions: {}

	jobs:
	shellcheck:
	name: ShellCheck
	runs-on: ubuntu-latest

	steps:
	- uses: actions/checkout@v3

	- name: Install prerequisites
	run: \|
	sudo apt update -y
	sudo apt install -y shellcheck jq
	mkdir ~/bin
	cat <<\EOF > ~/bin/sc2github
	#!/usr/bin/jq -rf
	.comments[] \|
	.gh_level = {"error": "error", "warning": "warning",
	"info": "notice", "style": "notice"}[.level] \|
	"::\(.gh_level) title=SC\(.code),file=\(.file),line=\(.line)," +
	"col=\(.column),endLine=\(.endLine),endColumn=\(.endColumn)::\(.message)"
	EOF
	chmod +x ~/bin/sc2github
	echo ~/bin >> "$GITHUB_PATH"

	- name: Check CI shell scripts
	# Run the "bash" with -o pipefail, not the default one without.
	shell: bash
	run: \|
	find ci -type f -name '*.sh' -print0 \|
	xargs -tr0 shellcheck -f json1 \|
	sc2github

	- name: Check .env files
	# Run even if the previous step failed. A failure in the previous step
	# will still fail the job as a whole.
	if: ${{ success() \|\| failure() }}
	# Run the "bash" with -o pipefail, not the default one without.
	shell: bash
	run: \|
	find ci/repo-config -type f -name '*.env' -print0 \|
	# SC2034 is the "$VAR appears unused" warning.
	xargs -tr0 shellcheck -f json1 -s bash --exclude=SC2034 \|
	sc2github

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