fix: don't fire event on disabled element

[eddyerburgh]

• Fixes 'Disabled' attribute on buttons is ignored during testing #395

[micgro42]

Unfortunately, this solution is too far-reaching. This also disables events, for example, on links with the disabled attribute.
While that might be the desired final state, it is something that needs to be asserted by tests. Just plainly disabling the trigger method in that case prevents me from doing so.