A big letter after a small letter looks incorrect on a keyboard,
because that is not normal German grammar and a keyboard is for
inputting text.
The key is also on the left side of the layout,
which makes äÄ not fit the visual flow.
Part-of: <https://gitlab.gnome.org/World/Phosh/squeekboard/-/merge_requests/611>
The altline-outline is primarily meant to be used for keys
that change the view, which is what these keys do.
Also changing it on the actions-view would make the layout not align
well anymore, as it is currently not possible to have 2 different
sizes with the altline-styling.
Part-of: <https://gitlab.gnome.org/World/Phosh/squeekboard/-/merge_requests/601>
MoonlightWave-12