Remove remaining ioutil usage (#1256)

Signed-off-by: Morten Linderud <[email protected]>

Author: Foxboron

cmd/cosign/cli/fulcio/fulcioverifier/fulcioverifier_test.go

@@ -17,7 +17,6 @@ package fulcioverifier
 
 import (
 	"fmt"
-	"io/ioutil"
 	"os"
 	"reflect"
 	"strings"
@@ -45,7 +44,7 @@ func TestGetAlternatePublicKey(t *testing.T) {
 	}
 	for _, tc := range tests {
 		filepath := fmt.Sprintf("%s/testdata/%s", wd, tc.file)
-		bytes, err := ioutil.ReadFile(filepath)
+		bytes, err := os.ReadFile(filepath)
 		if err != nil {
 			t.Fatalf("Failed to read testfile %s : %v", tc.file, err)
 		}

test/pkcs11_test.go

@@ -45,7 +45,6 @@ import (
 	"encoding/hex"
 	"encoding/pem"
 	"fmt"
-	"io/ioutil"
 	"math/big"
 	"os"
 	"strings"
@@ -351,7 +350,7 @@ func importKey(slotID uint) error {
 	keyLabelBytes := []byte(keyLabel)
 
 	r := strings.NewReader(rsaPrivKey)
-	pemBytes, err = ioutil.ReadAll(r)
+	pemBytes, err = os.ReadAll(r)
 	if err != nil {
 		return fmt.Errorf("unable to read pem")
 	}