The Lenovo X13s requires the wsa883x module to be enabled for audio support
[1]. I verified this by building this module in isolation (i.e. without
rebuilding the kernel and without otherwise changing the kernel config).
Booting with the added module gets audio working (with some extra userspace
bits from alsa-ucm and kernel-firmware).

CONFIG_SND_SOC_WSA883X=m

Could this module be built by default on aarch64 in openSUSE to get audio
working out-of-the-box more easily?

[1] Example config in a dev branch for the X13s's SoC:
https://github.com/jhovold/linux/blob/b2672eee6bf5e99bdc18d6a3e64df3dd96634059/arch/arm64/configs/johan_defconfig#L243C19-L243C19