Prometheus: Remove metadata endpoint (#53428) (#53433)

* remove prom metadata endpoint until we have a fix for detecting versions and implementations

* fix linting issue

(cherry picked from commit 7aeb8b4cdf)

Co-authored-by: Brendan O'Handley <brendan.ohandley@grafana.com>

public/app/plugins/datasource/prometheus/language_provider.ts

@@ -18,7 +18,6 @@ import { PrometheusDatasource } from './datasource';
 import {
   addLimitInfo,
   extractLabelMatchers,
-  fixSummariesMetadata,
   parseSelector,
   processHistogramMetrics,
   processLabels,
@@ -146,9 +145,19 @@ export default class PromQlLanguageProvider extends LanguageProvider {
   };
 
   async loadMetricsMetadata() {
-    this.metricsMetadata = fixSummariesMetadata(
-      await this.request('/api/v1/metadata', {}, {}, { showErrorAlert: false })
-    );
+    // The metadata endpoint is experimental and
+    // we have customers who are not implementing it.
+    // This is to be a temporary fix until the Observability Metrics Squad
+    // has time to implement the 2022Q3 plan
+    // to detect prometheus versions and implementations.
+    // This will allow us to see if endpoints such as api/v1/metadata
+    // are implemented or not and handle them as such
+    this.metricsMetadata = {};
+
+    // PREVIOUS IMPLEMENTATION FOR NOTES
+    // this.metricsMetadata = fixSummariesMetadata(
+    //   await this.request('/api/v1/metadata', {}, {}, { showErrorAlert: false })
+    // );
   }
 
   getLabelKeys(): string[] {