refactor: make MimeMessage.get_header() return Option<&str> #8306

	# GitHub Actions workflow
	# to test Node.js bindings.

	name: "node.js tests"

	# Cancel previously started workflow runs
	# when the branch is updated.
	concurrency:
	group: ${{ github.workflow }}-${{ github.ref }}
	cancel-in-progress: true

	on:
	pull_request:
	push:
	branches:
	- main

	jobs:
	tests:
	name: Tests
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	os: [ubuntu-latest, macos-latest, windows-latest]
	steps:
	- uses: actions/checkout@v4
	with:
	show-progress: false
	- uses: actions/setup-node@v4
	with:
	node-version: "18"
	- name: System info
	run: \|
	rustc -vV
	rustup -vV
	cargo -vV
	npm --version
	node --version

	- name: Cache node modules
	uses: actions/cache@v4
	with:
	path: \|
	${{ env.APPDATA }}/npm-cache
	~/.npm
	key: ${{ matrix.os }}-node-${{ hashFiles('**/package.json') }}

	- name: Cache cargo index
	uses: actions/cache@v4
	with:
	path: \|
	~/.cargo/registry/
	~/.cargo/git
	target
	key: ${{ matrix.os }}-cargo-index-${{ hashFiles('**/Cargo.lock') }}-2

	- name: Install dependencies & build
	if: steps.cache.outputs.cache-hit != 'true'
	working-directory: node
	run: npm install --verbose

	- name: Test
	timeout-minutes: 10
	working-directory: node
	run: npm run test
	env:
	CHATMAIL_DOMAIN: ${{ secrets.CHATMAIL_DOMAIN }}
	NODE_OPTIONS: "--force-node-api-uncaught-exceptions-policy=true"

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