Loki: Always fetch for new label keys in the QueryBuilder (#64597)

* always fetch new labels

* remove refreshLogLabels

public/app/plugins/datasource/loki/LanguageProvider.ts

@@ -386,12 +386,6 @@ export default class LokiLanguageProvider extends LanguageProvider {
     return [];
   }
 
-  async refreshLogLabels(forceRefresh?: boolean) {
-    if ((this.labelKeys && Date.now().valueOf() - this.labelFetchTs > LABEL_REFRESH_INTERVAL) || forceRefresh) {
-      await this.fetchLabels();
-    }
-  }
-
   /**
    * Fetch labels for a selector. This is cached by its args but also by the global timeRange currently selected as
    * they can change over requested time.

public/app/plugins/datasource/loki/querybuilder/components/LokiQueryBuilder.tsx

@@ -49,8 +49,7 @@ export const LokiQueryBuilder = React.memo<Props>(({ datasource, query, onChange
     const labelsToConsider = query.labels.filter((x) => x !== forLabel);
 
     if (labelsToConsider.length === 0) {
-      await datasource.languageProvider.refreshLogLabels();
-      return datasource.languageProvider.getLabelKeys();
+      return await datasource.languageProvider.fetchLabels();
     }
 
     const expr = lokiQueryModeller.renderLabels(labelsToConsider);