libsdl3 release 3.2.28+ds-2 for unstable

[dgit distro=debian split --quilt=gbp]
[dgit please-upload source=libsdl3 version=3.2.28+ds-2 upstream-tag=upstream/3.2.28+ds upstream=18351c44af6f78a9c6759eab43eecff67808d63f]