[BUGFIX] Use bootstrap 5 styles in RTE (#1091)

Author: Patta

Configuration/RTE/Default.yaml

@@ -17,7 +17,7 @@ editor:
             resource: "EXT:bootstrap_package/Resources/Public/CKEditor/Plugins/Table/plugin.min.js"
 
     config:
-        contentsCss: "EXT:bootstrap_package/Resources/Public/Css/bootstrap4-rte.min.css"
+        contentsCss: "EXT:bootstrap_package/Resources/Public/Css/bootstrap5-rte.min.css"
 
         stylesSet:
             - { name: "Lead", element: "p", attributes: { 'class': 'lead' } }