Merge pull request rails#47512 from etiennebarrie/deprecation-event-doc [ci-skip]

Remove sentence about the namespace of deprecation notification events

Author: p8

guides/source/active_support_instrumentation.md

@@ -760,8 +760,6 @@ INFO. The only ActiveStorage service that provides this hook so far is GCS.
 | `:gem_name`            | Name of the gem reporting the deprecation             |
 | `:deprecation_horizon` | Version where the deprecated behavior will be removed |
 
-NOTE: Each framework will also emit their own namespaced `deprecation` events.
-
 Exceptions
 ----------