gsk: Silence an import warning

Caused by the switch to no longer renamed ffi crates + flags being gated

gsk4/src/lib.rs

@@ -23,6 +23,7 @@ macro_rules! skip_assert_initialized {
 
 #[allow(clippy::derived_hash_with_manual_eq)]
 #[allow(clippy::too_many_arguments)]
+#[allow(unused_imports)]
 mod auto;
 
 pub mod builders;