Make performance checks more precise in e2e tests

[pomerantsev]

We should ideally have the same value in the if / else clauses in

accented/packages/devapp/test/main.spec.ts

Lines 1189 to 1193 in a89867a

	if (scan === 'short') {
	await expect(scanDuration).toBeLessThan(600);
	} else {
	await expect(scanDuration).toBeGreaterThan(200);
	}

, possibly by checking whether we're in CI or not.