[Benchmark] Fix benchmark dashboard failing to load metadata (#20026)

A previous PR removed these lines, causing metadata to no longer load in
the benchmark dashboard. This PR restores these lines.

Author: ianayl

devops/scripts/benchmarks/html/scripts.js

@@ -1606,6 +1606,12 @@ function fetchAndProcessData(url, isArchived = false) {
                 // Replace existing data for current data
                 loadedBenchmarkRuns = newRuns;
             }
+
+            // The following variables have same values regardless of whether
+            // we load archived or current data
+            benchmarkMetadata = data.metadata || benchmarkMetadata || {};
+            benchmarkTags = data.tags || benchmarkTags || {};
+
             initializeCharts();
         })
         .catch(error => {