fix: retruns -> returns

op-service/txmgr/txmgr_test.go

@@ -239,7 +239,7 @@ func (*mockBackend) ChainID(ctx context.Context) (*big.Int, error) {
 }
 
 // TransactionReceipt queries the mockBackend for a mined txHash. If none is
-// found, nil is returned for both return values. Otherwise, it retruns a
+// found, nil is returned for both return values. Otherwise, it returns a
 // receipt containing the txHash and the gasFeeCap used in the GasUsed to make
 // the value accessible from our test framework.
 func (b *mockBackend) TransactionReceipt(ctx context.Context, txHash common.Hash) (*types.Receipt, error) {