Update package version to 2.2.0 #7

	name: Push Tag

	on:
	pull_request:
	types:
	- closed
	branches:
	- "main"

	permissions:
	contents: write

	jobs:
	push-tag:
	if: github.event.pull_request.merged == true && startsWith(github.head_ref, 'release/')
	runs-on: ubuntu-22.04
	steps:
	- name: Generate a token
	id: generate_token
	uses: actions/create-github-app-token@v1
	with:
	app-id: ${{ secrets.APP_ID_OF_YUMEMI_TAG_PUSHER }}
	private-key: ${{ secrets.APP_PRIVATE_KEY_OF_YUMEMI_TAG_PUSHER }}
	- name: Checkout
	uses: actions/checkout@v4
	with:
	token: ${{ steps.generate_token.outputs.token }}
	- name: Extract a version
	id: extract_version
	run: \|
	version=$(echo ${{ github.head_ref }} \| sed -e 's/release\///')
	# Check version
	# See: https://github.com/dart-lang/pub_semver/blob/3175ba0a58a96fb23f8d68b5f5c44d1a5b30cc16/lib/src/patterns.dart#L6-L9
	if [[ ! "$version" =~ ^([0-9]+)\.([0-9]+)\.([0-9]+)(-([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)))?(\+([0-9A-Za-z-]+(\.[0-9A-Za-z-]+)))?$ ]]; then
	echo "Invalid version format: $version"
	exit 1
	fi
	echo "version=$version" >> "$GITHUB_OUTPUT"
	- name: Push a tag
	run: \|
	git tag "$VERSION"
	git push origin "$VERSION"
	env:
	VERSION: ${{ steps.extract_version.outputs.version }}

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