AR with HT+HR is inaccurate

[acrylic-style]

Describe the bug
AR with HT+HR is inaccurate (assuming the AR table on osu-wiki is correct)

This isn't a regression, it was broken since forever as you can see here:

ezpp/popup/index.js

Lines 177 to 192 in 7e1ceee

	case (MOD_HT + MOD_HR): {
	if (ar > 7) return 8.5;
	if (ar < 4) {
	ms = 2700 - 252 * ar;
	} else if (ar < 5) {
	ms = 1944 - 279 * (ar - 3);
	} else {
	ms = 1665 - 315 * (ar - 4);
	}
	if (ar < 6) {
	return 15 - ms / 120;
	} else if (ar > 7) {
	return 13 - ms / 150;
	}
	return 15 - ms / 120;
	}

To Reproduce
Steps to reproduce the behavior:

1. calculate AR with HT+HR

Expected behavior
show correct AR

Screenshots

Environment (please complete the following information):

• Browser:
  • Chrome
  • Firefox
• Version: N/A (just calculated using code on main branch)
• Beatmap URL: N/A