fix: os.MkdirTemp with t.TempDir (prometheus#15860)

Signed-off-by: Surya Prakash <surya0prakash@proton.me>

Author: suryaaprakassh

tsdb/tsdbutil/dir_locker_testutil.go

@@ -60,11 +60,7 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 
 	for _, c := range cases {
 		t.Run(fmt.Sprintf("%+v", c), func(t *testing.T) {
-			tmpdir, err := os.MkdirTemp("", "test")
-			require.NoError(t, err)
-			t.Cleanup(func() {
-				require.NoError(t, os.RemoveAll(tmpdir))
-			})
+			tmpdir := t.TempDir()
 
 			// Test preconditions (file already exists + lockfile option)
 			if c.fileAlreadyExists {
@@ -82,7 +78,7 @@ func TestDirLockerUsage(t *testing.T, open func(t *testing.T, data string, creat
 
 			// Check that the lockfile is always deleted
 			if !c.lockFileDisabled {
-				_, err = os.Stat(locker.path)
+				_, err := os.Stat(locker.path)
 				require.True(t, os.IsNotExist(err), "lockfile was not deleted")
 			}
 		})