Remove some now unnecessary Clippy lints allowances

src/rayon.rs

@@ -72,12 +72,10 @@ where
 
 impl<I: Iterator> ParallelIterator for I {}
 
-#[allow(dead_code)]
 pub fn join<A, B>(a: impl FnOnce() -> A, b: impl FnOnce() -> B) -> (A, B) {
     (a(), b())
 }
 
-#[allow(dead_code)]
 pub fn spawn<A>(a: impl FnOnce() -> A) -> A {
     a()
 }