fix(om2): clarify which Classic Buckets may be dropped (#2930)

Replace ambiguous "non-+Inf bucket" with "any bucket other than the
+Inf bucket" to avoid confusion with -+Inf notation. Since buckets are
cumulative, only the +Inf bucket must be kept.


Coded with Claude Sonnet 4.6.

Signed-off-by: György Krajcsovits <gyorgy.krajcsovits@grafana.com>
Co-authored-by: Bartlomiej Plotka <bwplotka@gmail.com>

Author: krajorama

docs/specs/om/open_metrics_spec_2_0.md

@@ -326,7 +326,7 @@ A Histogram Sample MAY have exemplars. The values of exemplars in a Histogram Sa
 
 Every Classic Bucket MUST have a threshold. Classic Bucket thresholds within a Sample MUST be unique. Classic Bucket thresholds MAY be negative.
 
-A Classic Bucket MUST count the number of measured values less than or equal to its threshold, including measured values that are also counted in lower buckets. This allows monitoring systems to drop any non-+Inf bucket for performance or anti-denial-of-service reasons in a way that loses granularity but is still a valid Histogram.
+A Classic Bucket MUST count the number of measured values less than or equal to its threshold, including measured values that are also counted in lower buckets. This allows monitoring systems to drop any bucket other than the +Inf bucket for performance or anti-denial-of-service reasons in a way that loses granularity but is still a valid Histogram.
 
 As an example, for a metric representing request latency in seconds with Classic Buckets and thresholds 1, 2, 3, and +Inf, it follows that value_1 <= value_2 <= value_3 <= value_+Inf. If ten requests took one second each, the values of the 1, 2, 3, and +Inf buckets will be all equal to 10.