Merge branch 'release/31.x'

* release/31.x:
  #4570 - Inefficient Knowledge Base SPARQL query for labels

inception/inception-kb/src/main/java/de/tudarmstadt/ukp/inception/kb/querybuilder/SPARQLQueryBuilder.java

@@ -641,7 +641,7 @@ private GraphPattern bindPrefLabelProperties(Variable aVariable)
         Iri pSubProperty = iri(kb.getSubPropertyIri());
         var primaryLabelPattern = aVariable
                 .has(PropertyPathBuilder.of(pSubProperty).zeroOrMore().build(), pLabel);
-        return optional(primaryLabelPattern);
+        return primaryLabelPattern;
     }
 
     /**