Fix publish-aarch64 job that still uses ubuntu-18.04

[curquiza]

When doing #3261 I forgot to update the publish-aarch64 job

meilisearch/.github/workflows/publish-binaries.yml

Lines 133 to 191 in c0ede6d

	publish-aarch64:
	name: Publish binary for aarch64
	runs-on: ${{ matrix.os }}
	needs: check-version
	strategy:
	fail-fast: false
	matrix:
	include:
	- build: aarch64
	os: ubuntu-18.04
	target: aarch64-unknown-linux-gnu
	linker: gcc-aarch64-linux-gnu
	use-cross: true
	asset_name: meilisearch-linux-aarch64
	steps:
	- name: Checkout repository
	uses: actions/checkout@v3
	- name: Installing Rust toolchain
	uses: actions-rs/toolchain@v1
	with:
	toolchain: stable
	profile: minimal
	target: ${{ matrix.target }}
	override: true
	- name: APT update
	run: |
	sudo apt update
	- name: Install target specific tools
	if: matrix.use-cross
	run: |
	sudo apt-get install -y ${{ matrix.linker }}
	- name: Configure target aarch64 GNU
	if: matrix.target == 'aarch64-unknown-linux-gnu'
	## Environment variable is not passed using env:
	## LD gold won't work with MUSL
	# env:
	# JEMALLOC_SYS_WITH_LG_PAGE: 16
	# RUSTFLAGS: '-Clink-arg=-fuse-ld=gold'
	run: |
	echo '[target.aarch64-unknown-linux-gnu]' >> ~/.cargo/config
	echo 'linker = "aarch64-linux-gnu-gcc"' >> ~/.cargo/config
	echo 'JEMALLOC_SYS_WITH_LG_PAGE=16' >> $GITHUB_ENV
	- name: Cargo build
	uses: actions-rs/cargo@v1
	with:
	command: build
	use-cross: ${{ matrix.use-cross }}
	args: --release --target ${{ matrix.target }}
	- name: List target output files
	run: ls -lR ./target
	- name: Upload the binary to release
	# No need to upload binaries for dry run (cron)
	if: github.event_name == 'release'
	uses: svenstaro/upload-release-action@2.4.0
	with:
	repo_token: ${{ secrets.MEILI_BOT_GH_PAT }}
	file: target/${{ matrix.target }}/release/meilisearch
	asset_name: ${{ matrix.asset_name }}
	tag: ${{ github.ref }}

Indeed, ubuntu-18.04 is removed 1st April, and v1.1.0 release is planned for 3rd April, so we need to update it before the release

[curquiza]

Fixed by #3568
Will be released in rc1 today