Ensure rented array is always returned (#104223)

Author: stevejgordon

src/libraries/System.Diagnostics.DiagnosticSource/src/System/Diagnostics/Metrics/Measurement.cs

@@ -115,7 +115,10 @@ public Measurement(T value, params ReadOnlySpan<KeyValuePair<string, object?>> t
             }
 
             if (count == 0)
+            {
+                ArrayPool<KeyValuePair<string, object?>>.Shared.Return(array);
                 return Instrument.EmptyTags;
+            }
 
             result = new KeyValuePair<string, object?>[count];
             array.AsSpan().Slice(0, count).CopyTo(result.AsSpan());