Native histograms are not experimental anymore

Signed-off-by: beorn7 <[email protected]>

Author: beorn7

README.md

@@ -37,8 +37,7 @@ Check out the [OpenMetrics project](https://openmetrics.io/) for the future of
 the data model and exposition format used by Prometheus and others.
 
 Note, though, that in an ironic twist of fate, the protobuf-based exposition
-format got revived to ease the implementation of experimental support for
-native histograms in Prometheus. Therefore, starting with v2.40.0, the
-Prometheus server is again capable of ingesting the protobuf-based exposition
-format (if the respective feature flag is enabled). Eventually, native
-histogram support will be added in some form to OpenMetrics, too.
+format got revived to suppert native histograms in Prometheus. Therefore,
+starting with v2.40.0, the Prometheus server is again capable of ingesting the
+protobuf-based exposition format. Eventually, native histogram support will be
+added in some form to OpenMetrics, too.

io/prometheus/client/metrics.proto

@@ -76,8 +76,7 @@ message Histogram {
 
   optional google.protobuf.Timestamp created_timestamp = 15;
 
-  // Everything below here is for native histograms (also known as sparse histograms).
-  // Native histograms are an experimental feature without stability guarantees.
+  // Everything below here is for native histograms (formerly known as sparse histograms).
 
   // schema defines the bucket schema. Currently, valid numbers are -4 <= n <= 8.
   // They are all for base-2 bucket schemas, where 1 is a bucket boundary in each case, and