chore: fix lints

src/backtrace/backtrace_rs.rs

@@ -23,6 +23,3 @@ impl super::Trace for Trace {
         unsafe { backtrace::trace_unsynchronized(cb) }
     }
 }
-
-pub use backtrace::Frame;
-pub use backtrace::Symbol;

src/backtrace/mod.rs

@@ -28,6 +28,9 @@ impl Symbol for backtrace::Symbol {
     }
 }
 
+// Methods in the trait are unused without feature flags, so we expect to get
+// a dead_code lint here.
+#[expect(dead_code)]
 pub trait Frame: Sized + Clone {
     type S: Symbol;