Fix Rust beta compiler errors 1.78.0-beta.1 (#5439)

* remove redundant imports

* fix test

* contains key

* fmt

* Merge branch 'unstable' into fix-beta-compiler

crypto/bls/src/generic_public_key_bytes.rs

@@ -6,7 +6,6 @@ use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_utils::hex::encode as hex_encode;
 use ssz::{Decode, Encode};
-use std::convert::TryInto;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;

crypto/bls/src/generic_signature_bytes.rs

@@ -7,7 +7,6 @@ use serde::de::{Deserialize, Deserializer};
 use serde::ser::{Serialize, Serializer};
 use serde_utils::hex::encode as hex_encode;
 use ssz::{Decode, Encode};
-use std::convert::TryInto;
 use std::fmt;
 use std::hash::{Hash, Hasher};
 use std::marker::PhantomData;

crypto/bls/src/impls/blst.rs

@@ -9,7 +9,6 @@ use crate::{
 pub use blst::min_pk as blst_core;
 use blst::{blst_scalar, BLST_ERROR};
 use rand::Rng;
-use std::iter::ExactSizeIterator;
 
 pub const DST: &[u8] = b"BLS_SIG_BLS12381G2_XMD:SHA-256_SSWU_RO_POP_";
 pub const RAND_BITS: usize = 64;