Implement Eq on aws-smithy-checksums::Error

Author: jjant

rust-runtime/aws-smithy-checksums/src/lib.rs

@@ -82,7 +82,7 @@ impl ChecksumAlgorithm {
     }
 }
 
-#[derive(Debug, PartialEq)]
+#[derive(Debug, PartialEq, Eq)]
 pub enum Error {
     UnknownChecksumAlgorithm(String),
 }