[BUGFIX] Return valid markup in localization panel

The localization panel in the list module now returns valid markup.

Resolves: #103286
Releases: main, 12.4
Change-Id: Ic91d3c767db901cc8a63a6ad27f4965a18797c8f
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/83214
Reviewed-by: Oliver Klee <typo3-coding@oliverklee.de>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Benjamin Franzke <ben@bnf.dev>
Reviewed-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Andreas Kienast <a.fernandez@scripting-base.de>
Tested-by: Oliver Klee <typo3-coding@oliverklee.de>
Tested-by: core-ci <typo3@b13.com>
Reviewed-by: Benjamin Franzke <ben@bnf.dev>

typo3/sysext/backend/Classes/RecordList/DatabaseRecordList.php

@@ -2006,7 +2006,7 @@ public function makeLocalizationPanel($table, $row, array $translations): string
                     : $title;
 
                 $out .= '<a href="' . htmlspecialchars($href) . '"'
-                    . '" class="btn btn-default t3js-action-localize"'
+                    . ' class="btn btn-default t3js-action-localize"'
                     . ' title="' . $title . '">'
                     . $lC . '</a> ';
             }