chore: Remove legacy prover code (#4357)

## What ❔

Remove bincode encoding for prover-related types(ones involved in both
prover and core)
Remove API mode config option. 
So, after this PR it will be not possible to:
* Run proof data handler in server mode
* Run prover gateway in client mode
* Save/get files(like witness inputs/final proofs) from Object store
which are encoded with bincode

## Why ❔

This code was left in codebase for the sake of backwards compatibility.
Now, since these changes were introduced in protocol version 27, it is
"safe" to remove them in version 29.

## Is this a breaking change?
- [x] Yes
- [ ] No

## Operational changes
<!-- Any config changes? Any new flags? Any changes to any scripts? -->
<!-- Please add anything that non-Matter Labs entities running their own
ZK Chain may need to know -->

## Checklist

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- [ ] PR title corresponds to the body of PR (we generate changelog
entries from PRs).
- [ ] Tests for the changes have been added / updated.
- [ ] Documentation comments have been added / updated.
- [ ] Code has been formatted via `zkstack dev fmt` and `zkstack dev
lint`.

Author: Artemka374

core/bin/zksync_server/src/node_builder.rs

@@ -334,15 +334,10 @@ impl MainNodeBuilder {
     }
 
     fn add_proof_data_handler_layer(mut self) -> anyhow::Result<Self> {
-        let gateway_config = try_load_config!(self.configs.prover_gateway);
-        let eth_proof_manager_config = self.configs.eth_proof_manager.clone();
-        let l2_chain_id = self.genesis_config.l2_chain_id;
-
         self.node.add_layer(ProofDataHandlerLayer::new(
             try_load_config!(self.configs.proof_data_handler_config),
-            eth_proof_manager_config,
-            l2_chain_id,
-            gateway_config.api_mode,
+            self.configs.eth_proof_manager.clone(),
+            self.genesis_config.l2_chain_id,
         ));
         Ok(self)
     }

core/lib/config/src/configs/fri_prover_gateway.rs

@@ -1,37 +1,17 @@
 use std::time::Duration;
 
-use serde::{Deserialize, Serialize};
-use smart_config::{
-    de::{Serde, WellKnown},
-    DescribeConfig, DeserializeConfig,
-};
+use smart_config::{DescribeConfig, DeserializeConfig};
 
 #[derive(Debug, Clone, PartialEq, DescribeConfig, DeserializeConfig)]
 pub struct FriProverGatewayConfig {
     pub api_url: String,
     #[config(default_t = Duration::from_secs(1000))]
     pub api_poll_duration: Duration,
-    #[config(default)]
-    pub api_mode: ApiMode,
     pub port: Option<u16>,
     // Configurations for prometheus
     pub prometheus_listener_port: Option<u16>,
 }
 
-#[derive(Debug, Clone, PartialEq, Default, Serialize, Deserialize)]
-pub enum ApiMode {
-    /// The legacy API mode, which is compatible with the old prover API.
-    #[default]
-    Legacy,
-    /// The new API mode, which is compatible with the prover cluster API.
-    ProverCluster,
-}
-
-impl WellKnown for ApiMode {
-    type Deserializer = Serde![str];
-    const DE: Self::Deserializer = Serde![str];
-}
-
 #[cfg(test)]
 mod tests {
     use smart_config::{testing::test_complete, Environment, Yaml};
@@ -42,7 +22,6 @@ mod tests {
         FriProverGatewayConfig {
             api_url: "http://private-dns-for-server".to_string(),
             api_poll_duration: Duration::from_secs(100),
-            api_mode: ApiMode::ProverCluster,
             port: Some(8080),
             prometheus_listener_port: Some(3316),
         }
@@ -53,7 +32,6 @@ mod tests {
         let env = r#"
             FRI_PROVER_GATEWAY_API_URL="http://private-dns-for-server"
             FRI_PROVER_GATEWAY_API_POLL_DURATION_SECS="100"
-            FRI_PROVER_GATEWAY_API_MODE=ProverCluster
             FRI_PROVER_GATEWAY_PORT=8080
             FRI_PROVER_GATEWAY_PROMETHEUS_LISTENER_PORT=3316
         "#;
@@ -70,7 +48,6 @@ mod tests {
         let yaml = r#"
           api_url: http://private-dns-for-server
           api_poll_duration_secs: 100
-          api_mode: ProverCluster
           port: 8080
           prometheus_listener_port: 3316
         "#;

core/lib/prover_interface/src/inputs.rs

@@ -7,9 +7,6 @@ use zksync_types::{
     basic_fri_types::Eip4844Blobs, witness_block_state::WitnessStorageState, L1BatchId,
     L1BatchNumber, ProtocolVersionId, H256, U256,
 };
-
-use crate::{FormatMarker, CBOR};
-
 const HASH_LEN: usize = H256::len_bytes();
 
 /// Metadata emitted by a Merkle tree after processing single storage log.
@@ -64,13 +61,10 @@ impl StorageLogMetadata {
 /// Merkle paths; if this is the case, the starting hashes are skipped and are the same
 /// as in the first path.
 #[derive(Debug, Clone, PartialEq, Serialize, Deserialize)]
-pub struct WitnessInputMerklePaths<FM: FormatMarker = CBOR> {
+pub struct WitnessInputMerklePaths {
     // Merkle paths and some auxiliary information for each read / write operation in a block.
     pub merkle_paths: Vec<StorageLogMetadata>,
     pub(crate) next_enumeration_index: u64,
-
-    #[serde(skip)]
-    pub(crate) _marker: std::marker::PhantomData<FM>,
 }
 
 impl StoredObject for WitnessInputMerklePaths {
@@ -106,7 +100,6 @@ impl WitnessInputMerklePaths {
         Self {
             merkle_paths: vec![],
             next_enumeration_index,
-            _marker: std::marker::PhantomData,
         }
     }
 
@@ -158,7 +151,7 @@ impl WitnessInputMerklePaths {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
-pub struct VMRunWitnessInputData<FM: FormatMarker = CBOR> {
+pub struct VMRunWitnessInputData {
     pub l1_batch_number: L1BatchNumber,
     pub used_bytecodes: HashMap<U256, Vec<[u8; 32]>>,
     pub initial_heap_content: Vec<(usize, U256)>,
@@ -170,12 +163,9 @@ pub struct VMRunWitnessInputData<FM: FormatMarker = CBOR> {
     pub storage_refunds: Vec<u32>,
     pub pubdata_costs: Vec<i32>,
     pub witness_block_state: WitnessStorageState,
-
-    #[serde(skip)]
-    pub _marker: std::marker::PhantomData<FM>,
 }
 
-impl StoredObject for VMRunWitnessInputData<CBOR> {
+impl StoredObject for VMRunWitnessInputData {
     const BUCKET: Bucket = Bucket::WitnessInput;
 
     type Key<'a> = L1BatchNumber;
@@ -203,9 +193,9 @@ impl StoredObject for VMRunWitnessInputData<CBOR> {
 }
 
 #[derive(Debug, Clone, Serialize, Deserialize, PartialEq)]
-pub struct WitnessInputData<FM: FormatMarker = CBOR> {
-    pub vm_run_data: VMRunWitnessInputData<FM>,
-    pub merkle_paths: WitnessInputMerklePaths<FM>,
+pub struct WitnessInputData {
+    pub vm_run_data: VMRunWitnessInputData,
+    pub merkle_paths: WitnessInputMerklePaths,
     pub previous_batch_metadata: L1BatchMetadataHashes,
     pub eip_4844_blobs: Eip4844Blobs,
 }
@@ -258,7 +248,7 @@ impl StoredObject for PublicWitnessInputData {
     type Key<'a> = L1BatchId;
 
     fn encode_key(key: Self::Key<'_>) -> String {
-        WitnessInputData::<CBOR>::encode_key(key)
+        WitnessInputData::encode_key(key)
     }
 
     fn serialize(&self) -> Result<Vec<u8>, BoxedError> {