adw-combo-row: Make the selected indicator a presentational element

Lukáš Tyrychtr requested to merge tyrylu/libadwaita:fix_icon_role into main

The image had the default role, so it was throwing a11y inspector warnings.

But, the selected state is communicated via the selected a11y state, so the image is just a presentational thing.

Fixes #736 (closed).

Merge request reports