Remove unused Matcher_Eq import in rust

PiperOrigin-RevId: 927449688

rust/cpp_kernel/extension.rs

diff --git a/rust/cpp_kernel/extension.rs b/rust/cpp_kernel/extension.rs
index 3da1539..dd3e6d7 100644
--- a/rust/cpp_kernel/extension.rs
+++ b/rust/cpp_kernel/extension.rs
@@ -8,7 +8,7 @@
 use super::*;
 use crate::__internal::entity_tag::*;
 use crate::__internal::runtime::_opaque_pointees::RawRepeatedFieldData;
-use crate::__internal::{EntityType, Enum, MatcherEq, Private, Singular};
+use crate::__internal::{EntityType, Enum, Private, Singular};
 use crate::extension::{ExtAccess, ExtClear, ExtGetMut, ExtHas};
 use crate::{ExtensionId, IntoMut, IntoView, MessageViewInterop, Proxied};