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>

validator_client/src/graffiti_file.rs

@@ -1,4 +1,4 @@
-use serde_derive::{Deserialize, Serialize};
+use serde::{Deserialize, Serialize};
 use std::collections::HashMap;
 use std::fs::File;
 use std::io::{prelude::*, BufReader};