ci: add scheduled build, use ubuntu-latest #143

	name: rustls-pemfile

	on:
	push:
	pull_request:
	merge_group:
	schedule:
	- cron: '0 18 * * *'

	jobs:
	rustfmt:
	runs-on: ubuntu-latest
	steps:
	- uses: dtolnay/rust-toolchain@stable
	with:
	components: rustfmt
	- uses: actions/checkout@v4
	- run: cargo fmt --all -- --check
	clippy:
	runs-on: ubuntu-latest
	steps:
	- uses: dtolnay/rust-toolchain@stable
	with:
	components: clippy
	- uses: actions/checkout@v4
	- run: cargo clippy --locked --all-features --all-targets
	rustdoc:
	runs-on: ubuntu-latest
	steps:
	- uses: dtolnay/rust-toolchain@stable
	- uses: actions/checkout@v4
	- run: cargo doc --locked --all-features
	build:
	name: "Build and test"
	runs-on: ${{ matrix.os }}
	strategy:
	matrix:
	# test a bunch of toolchains on ubuntu
	rust:
	- stable
	- beta
	- nightly
	os: [ubuntu-latest]
	# but only stable on macos/windows (slower platforms)
	include:
	- os: macos-latest
	rust: stable
	- os: windows-latest
	rust: stable
	steps:
	- name: Checkout sources
	uses: actions/checkout@v4

	- name: Install ${{ matrix.rust }} toolchain
	uses: dtolnay/rust-toolchain@master
	with:
	toolchain: ${{ matrix.rust }}
	targets: x86_64-unknown-none

	- name: cargo test (debug)
	run: cargo test --locked
	env:
	RUST_BACKTRACE: 1
	RUSTFLAGS: "-D warnings"

	- name: cargo test (release)
	run: cargo test --locked --release
	env:
	RUSTFLAGS: "-D warnings"

	# this target does _not_ include the libstd crate in its sysroot
	# it will catch unwanted usage of libstd in _dependencies_
	- name: cargo build no-std mode
	run: cargo build --locked --no-default-features --target x86_64-unknown-none
	env:
	RUSTFLAGS: "-D warnings"

Provide feedback