Increase video player scrubbing timeline height

[hjiangsu]

Pull Request Description

This is a minor PR which increases the height of Thunder's video player timeline. This should allow users to more easily scrub through a video.

Issue Being Fixed

Issue Number: https://lemmy.world/post/37544377

Screenshots / Recordings

Checklist

• If a new package was added, did you ensure it uses an appropriate license and is actively maintained?
• Did you use localized strings (and added appropriate descriptions) where applicable?
• Did you add semanticLabels where applicable for accessibility?