Add nix to default languages #1679

	name: CI
	on:
	pull_request:
	merge_group:

	jobs:
	test:
	name: Test
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	build: [stable, beta, nightly, macos, windows, msrv]
	include:
	- build: stable
	os: ubuntu-latest
	rust: stable
	- build: beta
	os: ubuntu-latest
	rust: beta
	- build: nightly
	os: ubuntu-latest
	rust: nightly
	- build: macos
	os: macos-latest
	rust: stable
	- build: windows
	os: windows-latest
	rust: stable
	- build: msrv
	os: ubuntu-20.04
	# sync MSRV with docs: guide/src/guide/installation.md and Cargo.toml
	rust: 1.70.0
	steps:
	- uses: actions/checkout@v3
	- name: Install Rust
	run: bash ci/install-rust.sh ${{ matrix.rust }}
	- name: Build and run tests
	run: cargo test --locked
	- name: Test no default
	run: cargo test --no-default-features

	rustfmt:
	name: Rustfmt
	runs-on: ubuntu-latest
	steps:
	- uses: actions/checkout@v3
	- name: Install Rust
	run: rustup update stable && rustup default stable && rustup component add rustfmt
	- run: cargo fmt --check

	# The success job is here to consolidate the total success/failure state of
	# all other jobs. This job is then included in the GitHub branch protection
	# rule which prevents merges unless all other jobs are passing. This makes
	# it easier to manage the list of jobs via this yml file and to prevent
	# accidentally adding new jobs without also updating the branch protections.
	success:
	name: Success gate
	if: always()
	needs:
	- test
	- rustfmt
	runs-on: ubuntu-latest
	steps:
	- run: jq --exit-status 'all(.result == "success")' <<< '${{ toJson(needs) }}'
	- name: Done
	run: exit 0

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