gha: tweak settings, add testing for "stable" and "oldstable" go #8

	name: CI

	on: [push, pull_request]

	# Default to 'contents: read', which grants actions to read commits. Any
	# permission not included is implicitly set to "none".
	#
	# see https://docs.github.com/en/actions/using-workflows/workflow-syntax-for-github-actions#permissions
	permissions:
	contents: read

	jobs:
	test:
	name: Test
	runs-on: ubuntu-latest
	timeout-minutes: 20 # guardrails timeout

	strategy:
	fail-fast: false
	matrix:
	go: ["1.12", "1.21", "1.22", "1.23", "oldstable", "stable"]

	steps:
	- name: Checkout repository
	uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0

	- name: Set up Go
	uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
	with:
	go-version: ${{ matrix.go }}

	- name: Test
	# Cannot enable shuffle for now because some tests rely on global state and order
	# run: go test -race -v -shuffle=on ./...
	run: go test -race -v ./...

	lint:
	name: Lint
	runs-on: ubuntu-latest
	timeout-minutes: 20 # guardrails timeout

	steps:
	- name: Checkout repository
	uses: actions/checkout@08c6903cd8c0fde910a37f88322edcfb5dd907a8 # v5.0.0

	- name: Set up Go
	uses: actions/setup-go@d35c59abb061a4a6fb18e82ac0862c26744d6ab5 # v5.5.0
	with:
	go-version: "stable"

	- name: Lint
	uses: golangci/golangci-lint-action@4afd733a84b1f43292c63897423277bb7f4313a9 # v8.0.0
	with:
	version: v2.4

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