Remove references to io/ioutil package

Signed-off-by: Austin Vazquez <macedonv@amazon.com>

pkg/testutils/cmd.go

@@ -15,7 +15,7 @@
 package testutils
 
 import (
-	"io/ioutil"
+	"io"
 	"os"
 
 	"github.com/containernetworking/cni/pkg/skel"
@@ -52,7 +52,7 @@ func CmdAdd(cniNetns, cniContainerID, cniIfname string, conf []byte, f func() er
 
 	var out []byte
 	if err == nil {
-		out, err = ioutil.ReadAll(r)
+		out, err = io.ReadAll(r)
 	}
 	os.Stdout = oldStdout
 

pkg/testutils/dns.go

@@ -16,7 +16,6 @@ package testutils
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"strings"
 
@@ -28,7 +27,7 @@ import (
 // an error if any occurs while creating/writing the file. It is the caller's
 // responsibility to remove the file.
 func TmpResolvConf(dnsConf types.DNS) (string, error) {
-	f, err := ioutil.TempFile("", "cni_test_resolv.conf")
+	f, err := os.CreateTemp("", "cni_test_resolv.conf")
 	if err != nil {
 		return "", fmt.Errorf("failed to get temp file for CNI test resolv.conf: %v", err)
 	}

pkg/testutils/echo/echo_test.go

@@ -2,7 +2,7 @@ package main_test
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"net"
 	"os/exec"
 	"strings"
@@ -74,7 +74,7 @@ var _ = Describe("Echosvr", func() {
 			defer conn.Close()
 
 			fmt.Fprintf(conn, "hello\n")
-			Expect(ioutil.ReadAll(conn)).To(Equal([]byte("hello")))
+			Expect(io.ReadAll(conn)).To(Equal([]byte("hello")))
 		})
 	})