It's still possible to disable via -Dvulkan=disabled
We force-disable it on Mac OS.
I don't know how to best handle it on Windows. Technically we don't need
it, because the Vulkan stuff we want is about dmabufs, but I have no
idea how to convince the build system to toggle the default to
"disabled" on Windows, so it has to stay enabled for now.
Linking on Windows can easily run out of memory, and limiting it
to a single link operation (i.e. disabling parallelization) should
be enough to avoid this problem.
CI currently fails with "fatal error LNK1318: Unexpected PDB error; OK (0) ''"
Google tells me it might be related to hitting a memory limit. Let's try
disabling debug for now.
GTK supports webm playback, which means a backend should always be
compiled.
The ffmpeg backend however is incomplete (no audio) and as such, we
don't want people to end up with it accidentally.
Since we don't want to drag an entire gstreamer build into our ci
on MacOs or msvc, explicitly disable the gstreame media backend there.
