Fix cmd tests by mocking builtin paths (#37369)

After 07ada3666b, PrepareConsoleLoggerLevel can fail in tests when
InstallLock is true, due to the incorrect config file is loaded. This PR
fixes cmd test setup by mocking builtin paths

Fixes #37368

---------

Co-authored-by: Morgan PEYRE <morgan.peyre@brickcode.tech>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>

cmd/cert_test.go

@@ -4,6 +4,7 @@
 package cmd
 
 import (
+	"io"
 	"path/filepath"
 	"testing"
 
@@ -107,6 +108,7 @@ func TestCertCommandFailures(t *testing.T) {
 	for _, c := range cases {
 		t.Run(c.name, func(t *testing.T) {
 			app := cmdCert()
+			app.Writer, app.ErrWriter = io.Discard, io.Discard
 			tempDir := t.TempDir()
 
 			certFile := filepath.Join(tempDir, "cert.pem")