[BUGFIX] Fix Dashboard RSS widgets cache life time handling

The SimpleFileBackend does not support cache life times, so RSS
feeds are currently cached "forever". Using the FileBackend instead
works as intended.

Resolves: #90562
Releases: master
Change-Id: I7481210ce58f597bdc644a1587da71091d172a4d
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63485


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Georg Ringer <georg.ringer@gmail.com>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Alexander Schnitzler <git@alexanderschnitzler.de>
Reviewed-by: Daniel Siepmann <coding@daniel-siepmann.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>

typo3/sysext/dashboard/ext_localconf.php

@@ -9,7 +9,7 @@ call_user_func(static function () {
         if (!is_array($GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['dashboard_rss'])) {
             $GLOBALS['TYPO3_CONF_VARS']['SYS']['caching']['cacheConfigurations']['dashboard_rss'] = [
                 'frontend' => \TYPO3\CMS\Core\Cache\Frontend\VariableFrontend::class,
-                'backend' => \TYPO3\CMS\Core\Cache\Backend\SimpleFileBackend::class,
+                'backend' => \TYPO3\CMS\Core\Cache\Backend\FileBackend::class,
                 'options' => [
                     'defaultLifetime' => 900,
                 ],