[BUGFIX] Initialize backenduser for RedirectServiceTest

RedirectsServiceTests simulate frontend requests
without executing them really, which prevents from
running through the FE Bootstrap stack, thus not all
needed stuff are setup correctly, thus throwing a
warning that $GLOBALS['BE_USER'] is not defined.

This patch initialize a backenduser for the
RedirectServiceTest to setup a correct BackendUser
object, thus mitigating this warning.

Resolves: #95548
Releases: master
Change-Id: I8318738e22761f172383db3b981779e331043f3f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/71518


Reviewed-by: Guido Schmechel <guido.schmechel@brandung.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Jochen <rothjochen@gmail.com>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Jochen <rothjochen@gmail.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>

typo3/sysext/redirects/Tests/Functional/Service/RedirectServiceTest.php

@@ -45,6 +45,12 @@ class RedirectServiceTest extends FunctionalTestCase
 
     protected array $testFilesToDelete = [];
 
+    protected function setUp(): void
+    {
+        parent::setUp();
+        $this->setUpBackendUserFromFixture(1);
+    }
+
     protected function tearDown(): void
     {
         foreach ($this->testFilesToDelete as $filename) {