[query] Update histograms.test based on new Prometheus release (#2488)

src/query/test/compatibility/testdata/histograms.test

@@ -151,22 +151,25 @@ eval instant at 50m histogram_quantile(0.5, rate(request_duration_seconds_bucket
 
 # A histogram with nonmonotonic bucket counts. This may happen when recording
 # rule evaluation or federation races scrape ingestion, causing some buckets
-# counts to be derived from fewer samples. The wrong answer we want to avoid
-# is for histogram_quantile(0.99, nonmonotonic_bucket) to return ~1000 instead
-# of 1.
+# counts to be derived from fewer samples.
 
 load 5m
-    nonmonotonic_bucket{le="0.1"}   0+1x10
-    nonmonotonic_bucket{le="1"}     0+9x10
-    nonmonotonic_bucket{le="10"}    0+8x10
-    nonmonotonic_bucket{le="100"}   0+8x10
+    nonmonotonic_bucket{le="0.1"}   0+2x10
+    nonmonotonic_bucket{le="1"}     0+1x10
+    nonmonotonic_bucket{le="10"}    0+5x10
+    nonmonotonic_bucket{le="100"}   0+4x10
     nonmonotonic_bucket{le="1000"}  0+9x10
-    nonmonotonic_bucket{le="+Inf"}  0+9x10
+    nonmonotonic_bucket{le="+Inf"}  0+8x10
 
 # Nonmonotonic buckets
-# TODO - enable after https://github.com/prometheus/prometheus/commit/7eaffa71802821087c8ee42dbda652453ec1f867 is released:
-# eval instant at 50m histogram_quantile(0.99, nonmonotonic_bucket)
-#    {} 0.989875
+eval instant at 50m histogram_quantile(0.01, nonmonotonic_bucket)
+    {} 0.0045
+
+eval instant at 50m histogram_quantile(0.5, nonmonotonic_bucket)
+    {} 8.5
+
+eval instant at 50m histogram_quantile(0.99, nonmonotonic_bucket)
+    {} 979.75
 
 # FAILING issue #48. Buckets with different representations of the same upper bound.
 # eval instant at 50m histogram_quantile(0.5, rate(mixed_bucket[5m]))