feat: enable native histogram ingestion by default (#9301)

* feat: enable native histogram ingestion by default

Signed-off-by: shuiyisong <xixing.sys@gmail.com>

* chore: add comments

Signed-off-by: shuiyisong <xixing.sys@gmail.com>

* fix: test

Signed-off-by: shuiyisong <xixing.sys@gmail.com>

---------

Signed-off-by: shuiyisong <xixing.sys@gmail.com>

src/session/src/protocol_ctx.rs

@@ -42,7 +42,6 @@ impl ProtocolCtx {
 ///     If true, all scope attributes will be promoted to the final table schema.
 ///     Along with the scope name, scope version and scope schema URL.
 /// - `with_metric_engine`
-/// - `experimental_enable_exponential_histogram`
 /// - `is_legacy`
 ///     If the user uses OTLP metrics ingestion before v0.16, it uses the old path.
 ///     So we call this path 'legacy'.
@@ -54,7 +53,6 @@ pub struct OtlpMetricCtx {
     pub resource_attrs: HashSet<String>,
     pub promote_scope_attrs: bool,
     pub with_metric_engine: bool,
-    pub experimental_enable_exponential_histogram: bool,
     pub is_legacy: bool,
     /// Set from the server's `otlp.experimental_enable_resource_info`; off
     /// means the resource descriptor is not synthesized at all.