Fix leaking handler in date format setup

[SlexAxton]

A coworker of mine patched this locally because we were experiencing progressive slow-downs the more we rendered certain pages with lots of dates.

They are adding and removing an event listener from cldr when we pass in options.timeZone, but since they are constructing the listener with a generator function, they aren't actually removing the one they added. I'll see if I can modify this function and check if that fixes it.

<3z, Alex

[jsf-clabot]

All committers have signed the CLA.

[rxaviers]

Thanks! ❤️

[rxaviers]

Published in https://github.com/globalizejs/globalize/releases/tag/1.4.0-alpha.1