chore: add lints to rpc (#1852)

Lior banned `as` repo-wide, unless absolutely necessary.

Nearly all as uses can be replaced with [Try]From which doesn't
have implicit coercions like as (we encountered several bugs due to these coercions).

Motivation: we are standardizing lints across the repo and CI,
instead of each crate having separate sets of lints.

Co-Authored-By: Gilad Chase <gilad@starkware.com>

crates/papyrus_rpc/Cargo.toml

@@ -62,7 +62,5 @@ starknet_client = { workspace = true, features = ["testing"] }
 strum.workspace = true
 strum_macros.workspace = true
 
-[lints.rust]
-# See [here](https://github.com/taiki-e/cargo-llvm-cov/issues/370) for a discussion on why this is
-# needed (from rust 1.80).
-unexpected_cfgs = { level = "warn", check-cfg = ['cfg(coverage_nightly)'] }
+[lints]
+workspace = true

crates/papyrus_rpc/src/v0_8/api/test.rs

@@ -2811,7 +2811,7 @@ async fn test_get_events(
     let mut parent_hash = BlockHash(felt!(GENESIS_HASH));
     let mut rw_txn = storage_writer.begin_rw_txn().unwrap();
     for (i, block_metadata) in block_metadatas.iter().enumerate() {
-        let block_number = BlockNumber(i as u64);
+        let block_number = BlockNumber(u64::try_from(i).expect("usize should fit in u64"));
         let block = block_metadata.generate_block(&mut rng, parent_hash, block_number);
 
         parent_hash = block.header.block_hash;
@@ -2863,7 +2863,10 @@ async fn test_get_events(
                 event_index_to_event.insert(
                     EventIndex(
                         TransactionIndex(
-                            BlockNumber(block_metadatas.len() as u64),
+                            BlockNumber(
+                                u64::try_from(block_metadatas.len())
+                                    .expect("usize should fit in u64"),
+                            ),
                             TransactionOffsetInBlock(i_transaction),
                         ),
                         EventIndexInTransactionOutput(i_event),
@@ -3336,7 +3339,7 @@ async fn get_events_page_size_too_big() {
 async fn get_events_too_many_keys() {
     let (module, _) = get_test_rpc_server_and_storage_writer::<JsonRpcServerImpl>();
     let keys = (0..get_test_rpc_config().max_events_keys + 1)
-        .map(|i| HashSet::from([EventKey(Felt::from(i as u128))]))
+        .map(|i| HashSet::from([EventKey(Felt::from(u128::try_from(i).unwrap()))]))
         .collect();
 
     // Create the filter.

crates/papyrus_rpc/src/v0_8/execution_test.rs

@@ -1515,7 +1515,7 @@ fn get_calldata_for_test_execution_info(
             expected_transaction_version,
             expected_caller_address,
             expected_max_fee,
-            felt!(expected_signature.len() as u64),
+            felt!(u64::try_from(expected_signature.len()).unwrap()),
         ],
         expected_signature,
         vec![
@@ -1540,7 +1540,11 @@ fn get_calldata_for_test_execution_info(
 
     Calldata(Arc::new(
         [
-            vec![*CONTRACT_ADDRESS.0.key(), entry_point_selector.0, felt!(calldata.len() as u64)],
+            vec![
+                *CONTRACT_ADDRESS.0.key(),
+                entry_point_selector.0,
+                felt!(u64::try_from(calldata.len()).unwrap()),
+            ],
             calldata,
         ]
         .iter()

crates/papyrus_rpc/src/v0_8/transaction.rs

@@ -1236,7 +1236,8 @@ fn l1_handler_message_hash(
     let to_address = Token::Bytes(contract_address.0.key().to_bytes_be().to_vec());
     let nonce = Token::Bytes(nonce.to_bytes_be().to_vec());
     let selector = Token::Bytes(entry_point_selector.0.to_bytes_be().to_vec());
-    let payload_length_as_felt = Felt::from(payload.len() as u64);
+    let payload_length_as_felt =
+        Felt::from(u64::try_from(payload.len()).expect("usize should fit in u64"));
     let payload_length = Token::Bytes(payload_length_as_felt.to_bytes_be().to_vec());
 
     let mut payload: Vec<_> =