WebGPUBackend: Fix `generateMipmaps` when used `copyFramebufferToTexture()` (#31163)

src/renderers/webgpu/WebGPUBackend.js

@@ -2394,6 +2394,12 @@ class WebGPUBackend extends Backend {
 
 		}
 
+		if ( texture.generateMipmaps ) {
+
+			this.textureUtils.generateMipmaps( texture );
+
+		}
+
 	}
 
 }