jmt: remove spurious Hasher: BorshSerialize + BorshDeserialize bounds (#116)

`borsh` changed their macro logic for bound inference in their 1.0 release. Unforunatley, the change causes borsh to infer spurious bounds on generic types in some cases. This PR removes the unnecessary bounds on types which are generic over a Hasher.

Author: preston-evans98

src/types/proof/definition.rs

@@ -37,6 +37,7 @@ pub struct SparseMerkleProof<H: SimpleHasher> {
     siblings: Vec<SparseMerkleNode>,
 
     /// A marker type showing which hash function is used in this proof.
+    #[borsh(bound(serialize = "", deserialize = ""))]
     phantom_hasher: PhantomData<H>,
 }
 
@@ -511,7 +512,9 @@ impl<H: SimpleHasher> SparseMerkleProof<H> {
 }
 
 #[derive(Debug, Serialize, Deserialize, borsh::BorshSerialize, borsh::BorshDeserialize)]
-pub struct UpdateMerkleProof<H: SimpleHasher>(Vec<SparseMerkleProof<H>>);
+pub struct UpdateMerkleProof<H: SimpleHasher>(
+    #[borsh(bound(serialize = "", deserialize = ""))] Vec<SparseMerkleProof<H>>,
+);
 
 impl<H: SimpleHasher> UpdateMerkleProof<H> {
     pub fn new(merkle_proofs: Vec<SparseMerkleProof<H>>) -> Self {