[DOCS] Fix PHP code example in changelog

Resolves: #94342
Releases: master, 10.4
Change-Id: Ia3d10d9b934788228ceb7c6ec0d3e1a67474b9f5
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/69436
Tested-by: core-ci <typo3@b13.com>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>

Author: o-ba

typo3/sysext/core/Documentation/Changelog/10.2/Deprecation-89718-LegacyPageTSconfigParsingLowlevelAPI.rst

@@ -46,14 +46,17 @@ Loading and parsing PageTSconfig on a low-level should be done via the new PHP c
 
 Usages for fetching all available PageTS of a page/rootline in one large string:
 
-:php:
-    $loader = GeneralUtility::makeInstance(PageTsConfigLoader::class);
-    $tsConfigString = $loader->load($rootLine);
+.. code-block:: php
 
+   $loader = GeneralUtility::makeInstance(PageTsConfigLoader::class);
+   $tsConfigString = $loader->load($rootLine);
 
-The string is parsed (and conditions are applied) with the Parser::
 
-   $parser = GeneralUtility::makeInstance(
+The string is parsed (and conditions are applied) with the Parser:
+
+.. code-block:: php
+
+      $parser = GeneralUtility::makeInstance(
        PageTsConfigParser::class,
        $typoScriptParser,
        $hashCache