Regression in mouse events which breaks tmux

[Tyriar]

VS Code issue: microsoft/vscode#192518

Repro:

1. Enable mouse events in tmux set -g mouse on in ~/.tmux.conf
2. Open tmux
3. Hold shift (to disable passthrough mouse events) and make a selection 🐛 it shows it being selected but as soon as mouseup happens, the selection disappears

It works if mouseup occurs outside the terminal element.

[Tyriar]

Removing the event listener changes from #4583 fixes it

xterm.js/src/browser/Terminal.ts

Lines 730 to 737 in 4241704

	if (!(events & CoreMouseEventType.UP)) {
	this._document!.removeEventListener('mouseup', requestedEvents.mouseup!);
	el.removeEventListener('mouseup', requestedEvents.mouseup!);
	requestedEvents.mouseup = null;
	} else if (!requestedEvents.mouseup) {
	el.addEventListener('mouseup', eventListeners.mouseup);
	requestedEvents.mouseup = eventListeners.mouseup;
	}