Beta compiler fixes (#5916)

* remove or update unused cfg

common/logging/src/async_record.rs

@@ -123,12 +123,10 @@ impl Serializer for ToSendSerializer {
         take(&mut self.kv, |kv| Box::new((kv, SingleKV(key, val))));
         Ok(())
     }
-    #[cfg(integer128)]
     fn emit_u128(&mut self, key: Key, val: u128) -> slog::Result {
         take(&mut self.kv, |kv| Box::new((kv, SingleKV(key, val))));
         Ok(())
     }
-    #[cfg(integer128)]
     fn emit_i128(&mut self, key: Key, val: i128) -> slog::Result {
         take(&mut self.kv, |kv| Box::new((kv, SingleKV(key, val))));
         Ok(())

common/validator_dir/src/validator_dir.rs

@@ -39,8 +39,6 @@ pub enum Error {
     /// generally caused by supplying an `amount` at deposit-time that is different to the one used
     /// at generation-time.
     Eth1DepositRootMismatch,
-    #[cfg(feature = "unencrypted_keys")]
-    SszKeypairError(String),
 }
 
 /// Information required to submit a deposit to the Eth1 deposit contract.