term_test.go: replace io/ioutil with io and os package

For golang/go#45557

Change-Id: I27cfebf64dd4597e3f00ea3fbb32d670619b5c45
GitHub-Last-Rev: 4c4433c530
GitHub-Pull-Request: golang/term#9
Reviewed-on: https://go-review.googlesource.com/c/term/+/430798
Run-TryBot: Ian Lance Taylor <iant@google.com>
Run-TryBot: Ian Lance Taylor <iant@golang.org>
Auto-Submit: Ian Lance Taylor <iant@google.com>
Reviewed-by: Ian Lance Taylor <iant@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
Reviewed-by: Cherry Mui <cherryyz@google.com>

term_test.go

@@ -5,7 +5,6 @@
 package term_test
 
 import (
-	"io/ioutil"
 	"os"
 	"runtime"
 	"testing"
@@ -14,7 +13,7 @@ import (
 )
 
 func TestIsTerminalTempFile(t *testing.T) {
-	file, err := ioutil.TempFile("", "TestIsTerminalTempFile")
+	file, err := os.CreateTemp("", "TestIsTerminalTempFile")
 	if err != nil {
 		t.Fatal(err)
 	}