Tests: Fix edge case in InternalBucketMetricValueTests

Same problem as in #26084.

core/src/test/java/org/elasticsearch/search/aggregations/pipeline/bucketmetrics/InternalBucketMetricValueTests.java

@@ -89,7 +89,11 @@ public class InternalBucketMetricValueTests extends InternalAggregationTestCase<
             name += randomAlphaOfLength(5);
             break;
         case 1:
-            value += between(1, 100);
+            if (Double.isFinite(value)) {
+                value += between(1, 100);
+            } else {
+                value = randomDoubleBetween(0, 100000, true);
+            }
             break;
         case 2:
             keys = Arrays.copyOf(keys, keys.length + 1);