Drop support for PHP 8.1

module/CLI/test-cli/Command/ImportShortUrlsTest.php

@@ -19,11 +19,7 @@ use function unlink;
 
 class ImportShortUrlsTest extends CliTestCase
 {
-    /**
-     * @var false|string|null
-     * @todo Use native type once PHP 8.1 support is dropped
-     */
-    private mixed $tempCsvFile = null;
+    private false|string|null $tempCsvFile = null;
 
     protected function setUp(): void
     {

module/Rest/test-api/Action/ListShortUrlsTest.php

@@ -169,7 +169,6 @@ class ListShortUrlsTest extends ApiTestCase
 
     public static function provideFilteredLists(): iterable
     {
-        // FIXME Cannot use enums in constants in PHP 8.1. Change this once support for PHP 8.1 is dropped
         $withDeviceLongUrls = static fn (array $shortUrl, ?array $longUrls = null) => [
             ...$shortUrl,
             'deviceLongUrls' => $longUrls ?? [