fix(sdk): typo in constructor docstring

Fixes a typo in the docstring for the constructor of the
CrossChainMessenger class.

.changeset/chilled-bats-warn.md

+---
+'@eth-optimism/sdk': patch
+---
+
+Fix typo in constructor docstring

packages/sdk/src/cross-chain-messenger.ts

@@ -64,7 +64,7 @@ export class CrossChainMessenger implements ICrossChainMessenger {
    *
    * @param opts Options for the provider.
    * @param opts.l1SignerOrProvider Signer or Provider for the L1 chain, or a JSON-RPC url.
-   * @param opts.l1SignerOrProvider Signer or Provider for the L2 chain, or a JSON-RPC url.
+   * @param opts.l2SignerOrProvider Signer or Provider for the L2 chain, or a JSON-RPC url.
    * @param opts.l1ChainId Chain ID for the L1 chain.
    * @param opts.depositConfirmationBlocks Optional number of blocks before a deposit is confirmed.
    * @param opts.l1BlockTimeSeconds Optional estimated block time in seconds for the L1 chain.