Suppress unused import warnings in generated code

rust-bindings/rust/src/lib.rs

@@ -14,6 +14,7 @@ extern crate lazy_static;
 use glib::Error;
 
 // code generated by gir
+#[allow(unused_imports)]
 mod auto;
 pub use crate::auto::functions::*;
 pub use crate::auto::*;