op-e2e: Remove unused TempDir function

op-e2e/e2eutils/io.go

-package e2eutils
-
-import (
-	"fmt"
-	"os"
-	"strings"
-	"testing"
-	"unicode"
-	"unicode/utf8"
-
-	"github.com/stretchr/testify/require"
-)
-
-func TempDir(t *testing.T) string {
-	// Drop unusual characters (such as path separators or
-	// characters interacting with globs) from the directory name to
-	// avoid surprising os.MkdirTemp behavior.
-	// Taken from the t.TempDir() implementation in the standard library.
-	mapper := func(r rune) rune {
-		if r < utf8.RuneSelf {
-			const allowed = "!#$%&()+,-.=@^_{}~ "
-			if '0' <= r && r <= '9' ||
-				'a' <= r && r <= 'z' ||
-				'A' <= r && r <= 'Z' {
-				return r
-			}
-			if strings.ContainsRune(allowed, r) {
-				return r
-			}
-		} else if unicode.IsLetter(r) || unicode.IsNumber(r) {
-			return r
-		}
-		return -1
-	}
-
-	dir, err := os.MkdirTemp("", strings.Map(mapper, fmt.Sprintf("op-e2e-%s", t.Name())))
-	require.NoError(t, err)
-
-	t.Cleanup(func() {
-		err := os.RemoveAll(dir)
-		if err != nil {
-			t.Logf("Error removing temp dir %s: %s", dir, err)
-		}
-	})
-
-	return dir
-}