ethclient: ensure the close of canceled context (#28349)

Author: keroro520

ethclient/ethclient_test.go

@@ -393,6 +393,7 @@ func testTransactionInBlockInterrupted(t *testing.T, client *rpc.Client) {
 	// Test tx in block interrupted.
 	ctx, cancel := context.WithCancel(context.Background())
 	cancel()
+	<-ctx.Done() // Ensure the close of the Done channel
 	tx, err := ec.TransactionInBlock(ctx, block.Hash(), 0)
 	if tx != nil {
 		t.Fatal("transaction should be nil")
@@ -666,6 +667,7 @@ func testTransactionSender(t *testing.T, client *rpc.Client) {
 	// TransactionSender. Ensure the server is not asked by canceling the context here.
 	canceledCtx, cancel := context.WithCancel(context.Background())
 	cancel()
+	<-canceledCtx.Done() // Ensure the close of the Done channel
 	sender1, err := ec.TransactionSender(canceledCtx, tx1, block2.Hash(), 0)
 	if err != nil {
 		t.Fatal(err)