ci: lock node version for worker tests

[AriPerkkio]

Description

• Ref. worker_threads stuck when passed execArgv: ["--inspect-brk"] nodejs/node#53648

vitest/test/config/test/exec-args.test.ts

Lines 5 to 26 in d7f23d0

	test.each([
	{ pool: 'forks', execArgv: ['--hash-seed=1', '--random-seed=1', '--no-opt'] },
	{ pool: 'threads', execArgv: ['--inspect-brk'] },
	{ pool: 'vmThreads', execArgv: ['--inspect-brk'] },
	] as const)('should pass execArgv to { pool: $pool } ', async ({ pool, execArgv }) => {
	const root = './fixtures/exec-args-fixtures'
	const fileToTest = `${pool}.test.ts`
	const vitest = await runVitest({
	root,
	include: [fileToTest],
	pool,
	poolOptions: {
	[pool]: {
	execArgv,
	},
	},
	})
	expect(vitest.stdout).toContain(`✓ ${fileToTest}`)
	expect(vitest.stderr).toBe('')
	})

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