fix: lint issues

Author: nicolasbrugneaux

packages/web3-eth/src/utils/prepare_transaction_for_signing.ts

@@ -44,8 +44,7 @@ const getEthereumjsTxDataFromTransaction = (
 
 	for (const [oldField, newField] of aliases) {
 		if (typeof txData[oldField] !== 'undefined') {
-			// @ts-expect-error
-			txData[newField] = txData[oldField];
+			txData[newField] = txData[oldField]!;
 			delete txData[oldField];
 		}
 	}

packages/web3-eth/test/unit/prepare_transaction_for_signing.test.ts

@@ -366,9 +366,7 @@ describe('prepareTransactionForSigning', () => {
 			context,
 		)) as TypedTransaction & { feeCurrency: string };
 
-		// @ts-expect-error
-		expect(spy.mock.lastCall[0].feeCurrency).toEqual(
-			'0x1234567890123456789012345678901234567890',
-		);
+		// @ts-expect-error feeCurrency is a custom field for testing here
+		expect(spy.mock.lastCall[0].feeCurrency).toBe('0x1234567890123456789012345678901234567890');
 	});
 });