fix some samples releasing a null surface texture

[radgeRayden]

No description provided.

[almarklein]

Out of curiosity, what happened before this change? Did it lead to a panic?

[rajveermalviya]

Looking through the implementation of wgpuSurfaceGetCurrentTexture & in wgpu-core, library will return null for all of these three cases (timeout, outdated, lost). So, the texture release there is not needed at all. Or we can conform to be consistent with all other functions which never return null for a wgpu object.

[radgeRayden]

Out of curiosity, what happened before this change? Did it lead to a panic?

In the C samples resizing the window would cause the application to hang. On my non C application for whatever reason I got the proper panic.

[almarklein]

In the C samples resizing the window would cause the application to hang. On my non C application for whatever reason I got the proper panic.

Hey, this sounds a lot like pygfx/wgpu-py#352 cc @Korijn