[wip] lib/dns: add test data for OPT record #803

	name: Go1.21
	on: [push]
	jobs:
	build:
	name: Build
	runs-on: ubuntu-latest
	steps:
	- name: Set up Go 1.21
	uses: actions/setup-go@v5
	with:
	go-version: '^1.21.7'
	id: go

	- name: Check out code into the Go module directory
	uses: actions/checkout@v4

	- name: Build
	run: make build

	- name: Test
	run: make test

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