web-sys: allow unused import warning

This import is only used if some features get used and it is way easier to just
quiet the warning when those features aren't used than to try and `cfg` this
import.

crates/web-sys/src/lib.rs

@@ -16,6 +16,7 @@
 extern crate js_sys;
 extern crate wasm_bindgen;
 
+#[allow(unused_imports)]
 use js_sys::Object;
 
 #[cfg(feature = "Window")]