fix: button receives pressed event in Flickable(#9521)

[eminfedar]

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Fixes: #9521

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[ogoffart]

Thanks for submitting a PR.
The delay is there on purpose because while scrolling, we don't want the press event to activate.
Maybe the 100ms is too long and can be adjusted. Or we'd use other heuristic.
But i think the behaviour that you see in bug #9521 is precisely because we got complaints that element would be shown as pressed while scrolling
(it was added in #1652 )