Suppress new result_unit_err clippy lint

serde/src/lib.rs

@@ -119,6 +119,7 @@
         // correctly used
         enum_glob_use,
         map_err_ignore,
+        result_unit_err,
         wildcard_imports,
         // not practical
         needless_pass_by_value,

serde_derive_internals/lib.rs

@@ -6,6 +6,7 @@
     allow(
         cognitive_complexity,
         redundant_field_names,
+        result_unit_err,
         trivially_copy_pass_by_ref,
         wildcard_in_or_patterns,
         // clippy bug: https://github.com/rust-lang/rust-clippy/issues/5704