[BUGFIX] Allow span tags in fieldInformation return

To be able to improve the layout of field information, the span tag is
added to the list of allowed tags in html.

Resolves: #84633
Releases: master, 8.7
Change-Id: If3a60002cb8b7a7473e96820bdb35ac9c8111bab
Reviewed-on: https://review.typo3.org/56573
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Tested-by: Andreas Fernandez <a.fernandez@scripting-base.de>
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Helmut Hummel <typo3@helhum.io>
Tested-by: Helmut Hummel <typo3@helhum.io>

typo3/sysext/backend/Classes/Form/NodeExpansion/FieldInformation.php

@@ -66,7 +66,7 @@ public function render(): array
             $options['renderData']['fieldInformationOptions'] = $orderedFieldInformationConfiguration['options'] ?? [];
             $informationResult = $this->nodeFactory->create($options)->render();
 
-            $allowedTags = '<a><br><br/><div><em><i><p><strong>';
+            $allowedTags = '<a><br><br/><div><em><i><p><strong><span>';
             if (strip_tags($informationResult['html'], $allowedTags) !== $informationResult['html']) {
                 throw new \RuntimeException(
                     'The field information API supports only a limited number of HTML tags within the result'