unix: use slices.{Equal,Sort} in tests

Same as CL 587655 and CL 690475 did for package syscall tests.

Change-Id: Ie3c8726a4e2c859b5d7992ea1baec14083b9fdba
Reviewed-on: https://go-review.googlesource.com/c/sys/+/708558
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Florian Lehner <lehner.florian86@gmail.com>
Reviewed-by: Carlos Amedee <carlos@golang.org>
Auto-Submit: Tobias Klauser <tobias.klauser@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Sean Liao <sean@liao.dev>

unix/dirent_test.go

@@ -12,7 +12,7 @@ import (
 	"os"
 	"path/filepath"
 	"runtime"
-	"sort"
+	"slices"
 	"strconv"
 	"strings"
 	"testing"
@@ -72,7 +72,7 @@ func TestDirent(t *testing.T) {
 		}
 	}
 
-	sort.Strings(names)
+	slices.Sort(names)
 	t.Logf("names: %q", names)
 
 	if len(names) != 10 {
@@ -145,9 +145,9 @@ func TestDirentRepeat(t *testing.T) {
 	}
 
 	// Check results
-	sort.Strings(files)
-	sort.Strings(files2)
-	if strings.Join(files, "|") != strings.Join(files2, "|") {
+	slices.Sort(files)
+	slices.Sort(files2)
+	if !slices.Equal(files, files2) {
 		t.Errorf("bad file list: want\n%q\ngot\n%q", files, files2)
 	}
 }