fix(cardano-blockchain-types): remove serde_json

Signed-off-by: bkioshn <[email protected]>

Author: bkioshn

rust/cardano-blockchain-types/Cargo.toml

@@ -38,4 +38,3 @@ num-traits = "0.2.19"
 ed25519-dalek = "2.1.1"
 serde = "1.0.210"
 num-bigint = "0.4.6"
-serde_json = "1.0.134"