Remove serde derive references (#4830)

* remove remaining uses of serde_derive

* fix lockfile

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Co-authored-by: João Oliveira <hello@jxs.pt>

common/monitoring_api/src/types.rs

@@ -1,7 +1,7 @@
 use std::time::{SystemTime, UNIX_EPOCH};
 
 use eth2::lighthouse::{ProcessHealth, SystemHealth};
-use serde_derive::{Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 
 pub const VERSION: u64 = 1;
 pub const CLIENT_NAME: &str = "lighthouse";