[TASK] Disable failing unit-case test data set

Since recently upgraded PHP-version the
10mb big xml unit test failes.

The `\LIBXML_PARSEHUGE` xml option could
be used to mitigate this case but would
not explain the change from PHP yet.

Thus the decision has been made to disable
the failing data set as a temporary solution
to avoid disturbance for core contribution
until this issue has been investigated and
reported to PHP itself.

Resolves: #104218
Releases: main, 12.4, 11.5
Change-Id: Ifef4f18818e661312b9e56e013bb8f479146b806
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84849


Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Stefan Bürk <stefan@buerk.tech>

typo3/sysext/core/Tests/Unit/Serializer/Typo3XmlParserTest.php

@@ -352,7 +352,9 @@ final class Typo3XmlParserTest extends UnitTestCase
         return [
             '1mb' => [1],
             '5mb' => [5],
-            '10mb' => [10],
+            // @todo Since 8.1.29 | 8.2.20 | 8.3.8 this case is broken. Needs deeper investigation and issue report
+            //       on php itself. Using `\LIBXML_PARSEHUGE` would mitigate the issue, but have not been used before.
+            // '10mb' => [10],
         ];
     }
 
@@ -360,15 +362,15 @@ final class Typo3XmlParserTest extends UnitTestCase
     #[Test]
     public function decodeHandlesBigXmlContent(int $megabytes): void
     {
+        $testValue = str_repeat('1', $megabytes * 1024 * 1024);
         $input = '<?xml version="1.0" encoding="utf-8" standalone="yes"?>
             <T3FlexForms>
                 <data>
                     <field index="settings.persistenceIdentifier">
-                        <value index="vDEF">' . str_repeat('1', $megabytes * 1024 * 1024) . '</value>
+                        <value index="vDEF">' . $testValue . '</value>
                     </field>
                 </data>
             </T3FlexForms>';
-        $testValue = str_repeat('1', $megabytes * 1024 * 1024);
         $xmlDecoder = new Typo3XmlParser();
         $expected = [
             'data' => [