Fix case of OS name #22

	name: CI
	on:
	push:
	branches: [main]
	pull_request:
	branches: [main]
	jobs:
	build:
	name: Build
	runs-on: ubuntu-latest
	timeout-minutes: 60
	steps:
	- uses: actions/checkout@v4
	- name: Install mdbook
	uses: taiki-e/install-action@mdbook
	- name: Install mdbook linkcheck
	uses: taiki-e/install-action@mdbook-linkcheck
	- run: mdbook build docs/en
	- run: mdbook build docs/ja
	- name: Deploy
	run: \|
	mkdir -p book
	mv docs/en/book book/en
	mv docs/ja/book book/ja
	cd book
	git init
	git add .
	git -c user.name='ci' -c user.email='ci' commit -m 'Deploy OpenRR Book'
	git push -f -q https://git:${{ secrets.github_token }}@github.com/${{ github.repository }} HEAD:gh-pages
	if: github.event_name == 'push' && github.event.ref == 'refs/heads/main' && github.repository_owner == 'openrr'

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