[GTK] Remove GTK-specific media-controller-auto-hide-pause-expected.txt

https://bugs.webkit.org/show_bug.cgi?id=271753

Reviewed by Philippe Normand.

The test has been failing with GTK because the GTK-specific expectation
file is outdated. The test passes with the original expectation file.

* LayoutTests/platform/gtk/media/modern-media-controls/media-controller/media-controller-auto-hide-pause-expected.txt: Removed.

Canonical link: https://commits.webkit.org/276728@main