Update EIP-6110: change request to flat encoding

EIPS/eip-6110.md

@@ -62,19 +62,15 @@ The structure denoting the new deposit operation consists of the following field
 4. `signature: Bytes96`
 5. `index: uint64`
 
-Deposits are a type of [EIP-7685](./eip-7685.md) request, therefore the encoding of the structure must be computed using the `DEPOSIT_REQUEST_TYPE` byte:
+Deposits are a type of [EIP-7685](./eip-7685.md) request, with the following encoding:
 
 ```python
-deposit_request_rlp = DEPOSIT_REQUEST_TYPE + rlp([
-    pubkey,
-    withdrawal_credentials,
-    amount,
-    signature,
-    index
-])
+request_type = DEPOSIT_REQUEST_TYPE
+request_data = pubkey ++ withdrawal_credentials ++ amount ++ signature ++ index
 ```
 
-The encoded deposits will be included in the header and body as generic requests following the format defined by EIP-7685.
+Note that the request payload is just the concatenation of the elements returned by the contract.
+The encoded deposits will be included in the header and body following the format defined by EIP-7685.
 
 #### Block validity
 
@@ -94,17 +90,15 @@ def parse_deposit_data(deposit_event_data) -> bytes[]:
 def little_endian_to_uint64(data: bytes) -> uint64:
     return uint64(int.from_bytes(data, 'little'))
 
-def event_data_to_deposit_request_rlp(deposit_event_data) -> bytes:
+def event_data_to_deposit_request(deposit_event_data) -> bytes:
     deposit_data = parse_deposit_data(deposit_event_data)
     pubkey = Bytes48(deposit_data[0])
     withdrawal_credentials = Bytes32(deposit_data[1])
-    amount = little_endian_to_uint64(deposit_data[2])
+    amount = deposit_data[2]   # 8 bytes uint64 LE
     signature = Bytes96(deposit_data[3])
-    index = little_endian_to_uint64(deposit_data[4])
+    index = deposit_data[4]    # 8 bytes uint64 LE
 
-    return DEPOSIT_REQUEST_TYPE + rlp([
-        pubkey, withdrawal_credentials, amount, signature, index
-    ])
+    return DEPOSIT_REQUEST_TYPE + pubkey + withdrawal_credentials + amount + signature + index
 
 # Obtain receipts from block execution result
 receipts = block.execution_result.receipts
@@ -114,8 +108,8 @@ expected_deposit_requests = []
 for receipt in receipts:
     for log in receipt.logs:
         if log.address == DEPOSIT_CONTRACT_ADDRESS:
-            deposit_request_rlp = event_data_to_deposit_request_rlp(log.data)
-            expected_deposit_requests.append(deposit_request_rlp)
+            deposit_request = event_data_to_deposit_request(log.data)
+            expected_deposit_requests.append(deposit_request)
 
 deposit_requests = [req for req in block.body.requests if req[:1] == DEPOSIT_REQUEST_TYPE]