Fix depth prepass with msaa on webgpu

[beicause]

Objective

Fixes #19148.
Should fix #19177, too, because wgpu webgl2 just doesn't support sampling depth or creating multisampled texture with TEXTURE_BINDING.

Solution

feature="webgl" and feature="webgpu" can enable together(webgpu overrides webgl), so we should bind multisampled depth texture even webgl feature is enabled.

Testing

Run decal example

[JMS55]

Rather than using cfg, we should be checking adapter info for the current backend imo.

[beicause]

Rather than using cfg, we should be checking adapter info for the current backend imo.

This might not be necessary and is beyond the scope of this PR. We use feature gating for webgl/webgpu in many places and it doesn't have runtime checks overhead.