WebGPURenderer: Fix MSAA using mipmap levels (#31544)

* WebGPU: Fix MSAA using mipmap levels

* Change comment to link to official specification

src/renderers/webgpu/utils/WebGPUTextureUtils.js

@@ -266,6 +266,7 @@ class WebGPUTextureUtils {
 
 			msaaTextureDescriptorGPU.label = msaaTextureDescriptorGPU.label + '-msaa';
 			msaaTextureDescriptorGPU.sampleCount = samples;
+			msaaTextureDescriptorGPU.mipLevelCount = 1; // See https://www.w3.org/TR/webgpu/#texture-creation
 
 			textureData.msaaTexture = backend.device.createTexture( msaaTextureDescriptorGPU );