refactor: move from io/ioutil to io and os package (#17109)

The io/ioutil package has been deprecated as of Go 1.16, see
https://golang.org/doc/go1.16#ioutil. This commit replaces the existing
io/ioutil functions with their new definitions in io and os packages.

Signed-off-by: Eng Zer Jun <engzerjun@gmail.com>

Co-authored-by: techknowlogick <techknowlogick@gitea.io>

integrations/create_no_session_test.go

@@ -5,7 +5,6 @@
 package integrations
 
 import (
-	"io/ioutil"
 	"net/http"
 	"net/http/httptest"
 	"os"
@@ -69,7 +68,7 @@ func TestSessionFileCreation(t *testing.T) {
 	config.Provider = "file"
 
 	// Now create a temporaryDirectory
-	tmpDir, err := ioutil.TempDir("", "sessions")
+	tmpDir, err := os.MkdirTemp("", "sessions")
 	assert.NoError(t, err)
 	defer func() {
 		if _, err := os.Stat(tmpDir); !os.IsNotExist(err) {