autoplay continues in safari when slideshow is outside of viewport

I have a wraparound flickity slideshow with adaptiveHeight and autoPlay enabled.

on Chrome, when I scroll past the slideshow (with slideshow now outside/above the viewport), the slideshow stops autoscrolling (expected).
but on Safari (mac, Version 17.2.1 (19617.1.17.11.12)), the slideshow continues to autoplay, causing the content below the slideshow (the content that is visible in the viewport of the browser) to shift up and down to accommodate the adaptive height of the slideshow. how can I stop the slideshow from playing in safari when it's not in the viewport?

**Test case:** https://codepen.io/pirco/pen/bGZZyWw

https://github.com/metafizzy/flickity/assets/146350/6a689eab-81ab-4e62-8065-5edc86b804b5

Start by reproducing the behavior in the linked CodePen with Safari 17.2.1, focusing on the interaction between autoPlay, adaptiveHeight, and the slideshow leaving the viewport. Compare Safari with Chrome and verify that autoplay stops outside the viewport without shifting visible content; the payload does not name repository files or tests.

Written by the indexing model from the issue text.