Update bootstrap-hover-dropdown for Bootstrap 5

[derek-ye]

• Updated '.open' with '.show' because '.open' deprecated in BS5 (https://getbootstrap.com/docs/5.0/components/dropdowns/#usage)

[PetrDlouhy]

Maybe I have something misconfigured in my project, but I had to change line 119 to:

$parent.children(".dropdown-menu").addClass('show');

to make this work with Bootstrap 5.

And also I changed line 50 to:

if(!$parent.hasClass('show') && !($this.is(event.target) || $parent.is(event.target))) {

otherwise the hover action was unreliable.