chore: use trait fn for setting both input fields (#12426)

Author: mattsse

crates/cast/src/tx.rs

@@ -9,7 +9,7 @@ use alloy_network::{
 };
 use alloy_primitives::{Address, Bytes, TxKind, U256, hex};
 use alloy_provider::Provider;
-use alloy_rpc_types::{AccessList, Authorization, TransactionInput, TransactionRequest};
+use alloy_rpc_types::{AccessList, Authorization, TransactionInputKind, TransactionRequest};
 use alloy_serde::WithOtherFields;
 use alloy_signer::Signer;
 use alloy_transport::TransportError;
@@ -317,8 +317,7 @@ impl<P: Provider<AnyNetwork>> CastTxBuilder<P, InputState> {
         self.tx.set_kind(self.state.kind);
 
         // we set both fields to the same value because some nodes only accept the legacy `data` field: <https://github.com/foundry-rs/foundry/issues/7764#issuecomment-2210453249>
-        let input = Bytes::copy_from_slice(&self.state.input);
-        self.tx.input = TransactionInput { input: Some(input.clone()), data: Some(input) };
+        self.tx.set_input_kind(self.state.input.clone(), TransactionInputKind::Both);
 
         self.tx.set_from(from);
         self.tx.set_chain_id(self.chain.id());
@@ -443,6 +442,7 @@ impl<P, S> CastTxBuilder<P, S>
 where
     P: Provider<AnyNetwork>,
 {
+    /// Populates the blob sidecar for the transaction if any blob data was provided.
     pub fn with_blob_data(mut self, blob_data: Option<Vec<u8>>) -> Result<Self> {
         let Some(blob_data) = blob_data else { return Ok(self) };