added MONAD_SYSTEM_ADDRESS (#12585)

* added MONAD_SYSTEM_ADDRESS

* modified comments

* chore: rsutfmt

---------

Co-authored-by: Matthias Seitz <[email protected]>

Author: Jayakumar2812

crates/common/src/constants.rs

@@ -39,6 +39,9 @@ pub const ARBITRUM_SENDER: Address = address!("0x0000000000000000000000000000000
 /// See also <https://github.com/ethereum-optimism/optimism/blob/65ec61dde94ffa93342728d324fecf474d228e1f/specs/deposits.md#l1-attributes-deposited-transaction>
 pub const OPTIMISM_SYSTEM_ADDRESS: Address = address!("0xdeaddeaddeaddeaddeaddeaddeaddeaddead0001");
 
+/// The system address, the sender of the first transaction in every block:
+pub const MONAD_SYSTEM_ADDRESS: Address = address!("0x6f49a8F621353f12378d0046E7d7e4b9B249DC9e");
+
 /// Transaction identifier of System transaction types
 pub const SYSTEM_TRANSACTION_TYPE: u8 = 126;
 
@@ -52,9 +55,10 @@ pub const TYPE_BINDING_PREFIX: &str = "string constant schema_";
 ///
 /// Transactions from these senders usually don't have a any fee information OR set absurdly high fees that exceed the gas limit (See: <https://github.com/foundry-rs/foundry/pull/10608>)
 ///
-/// See: [ARBITRUM_SENDER], [OPTIMISM_SYSTEM_ADDRESS] and [Address::ZERO]
+/// See: [ARBITRUM_SENDER], [OPTIMISM_SYSTEM_ADDRESS], [MONAD_SYSTEM_ADDRESS] and [Address::ZERO]
 pub fn is_known_system_sender(sender: Address) -> bool {
-    [ARBITRUM_SENDER, OPTIMISM_SYSTEM_ADDRESS, Address::ZERO].contains(&sender)
+    [ARBITRUM_SENDER, OPTIMISM_SYSTEM_ADDRESS, MONAD_SYSTEM_ADDRESS, Address::ZERO]
+        .contains(&sender)
 }
 
 pub fn is_impersonated_tx(tx: &AnyTxEnvelope) -> bool {