[SDK] Fix stray keccak256 reference (#7089)

## Summary
- remove unused `keccak256` import
- clean up unused statement in `resolve-l2-name`

## Testing
- `pnpm test` *(fails: EHOSTUNREACH)*

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## PR-Codex overview
This PR removes an unused import of `keccak256` from the `resolve-l2-name.ts` file, streamlining the code by eliminating unnecessary references.

### Detailed summary
- Removed the unused import of `keccak256` from the file `packages/thirdweb/src/extensions/ens/resolve-l2-name.ts`.

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Author: joaquim-verges

packages/thirdweb/src/extensions/ens/resolve-l2-name.ts

@@ -4,7 +4,6 @@ import * as ox__Bytes from "ox/Bytes";
 import * as ox__Ens from "ox/Ens";
 import * as ox__Hash from "ox/Hash";
 import * as ox__Hex from "ox/Hex";
-import { keccak256 } from "viem";
 import type { Chain } from "../../chains/types.js";
 import type { ThirdwebClient } from "../../client/client.js";
 import { getContract } from "../../contract/contract.js";
@@ -47,7 +46,6 @@ const convertReverseNodeToBytes = (address: Address, chainId: number) => {
       [reverseNode, addressNode],
     ),
   );
-  keccak256;
   return addressReverseNode;
 };