remove unused lifetime parameter from utils::calculate_hash

This doesn't trigger a warning before rustc 1.58.0, for whatever reason.

src/utils.rs

@@ -112,7 +112,7 @@ where
 }
 
 #[tracing::instrument(skip(keys))]
-pub(crate) fn calculate_hash<'a, I, T>(keys: I) -> Vec<u8>
+pub(crate) fn calculate_hash<I, T>(keys: I) -> Vec<u8>
 where
     I: IntoIterator<Item = T>,
     T: AsRef<[u8]>,