Request: `Option<NonZeroU32>` instead of u32 in `wlr_layer::LayerSurfaceConfigure.new_size`

[Koranir]

https://github.com/Smithay/client-toolkit/blob/da3e5c573a261117cbd70dc079a333bcd610a1d7/src/shell/wlr_layer/mod.rs#L269

The docs say that if the value is zero, you can choose any length for the axis you want. This seems like something Option::unwrap_or would be useful for instead of doing it manually.