Orchard: remove unused imports

zebra-chain/src/orchard/action.rs

@@ -5,8 +5,7 @@ use halo2::pasta::pallas;
 use crate::{
     primitives::redpallas::{self, SpendAuth},
     serialization::{
-        serde_helpers, ReadZcashExt, SerializationError, WriteZcashExt, ZcashDeserialize,
-        ZcashSerialize,
+        serde_helpers, ReadZcashExt, SerializationError, ZcashDeserialize, ZcashSerialize,
     },
 };
 

zebra-chain/src/orchard/keys.rs

@@ -9,7 +9,7 @@
 mod tests;
 
 use std::{
-    convert::{From, Into, TryFrom, TryInto},
+    convert::{From, Into, TryFrom},
     fmt,
     io::{self, Write},
     str::FromStr,

zebra-chain/src/primitives/proofs/halo2.rs

@@ -1,7 +1,7 @@
 use serde::{Deserialize, Serialize};
 use std::{fmt, io};
 
-use crate::serialization::{serde_helpers, SerializationError, ZcashDeserialize, ZcashSerialize};
+use crate::serialization::{SerializationError, ZcashDeserialize, ZcashSerialize};
 
 /// An encoding of a Halo2 proof, as used in [Zcash][halo2].
 ///

zebra-chain/src/primitives/redpallas/signing_key.rs

@@ -1,7 +1,4 @@
-use std::{
-    convert::{TryFrom, TryInto},
-    marker::PhantomData,
-};
+use std::convert::TryFrom;
 
 use halo2::arithmetic::FieldExt;
 use halo2::pasta::pallas;