Remove 'beta warning' for auto attach (#3287)

* Officially introduce Kubernetes APM auto-attach

---------

Co-authored-by: Kayla Reopelle <[email protected]>

Author: hannahramadan

CHANGELOG.md

@@ -2,6 +2,10 @@
 
 ## dev
 
+- **Feature: One-step instrumentation for Kubernetes**
+  
+  The Kubernetes APM auto-attach automatically instruments applications and manages agent upgrades within Kubernetes deployments. This feature has exited preview and is now generally avaliable. Learn more about [Kubernetes auto-attach](https://docs.newrelic.com/docs/kubernetes-pixie/kubernetes-integration/installation/k8s-agent-operator/). [PR#2635](https://github.com/newrelic/newrelic-ruby-agent/pull/2635) [PR#3287](https://github.com/newrelic/newrelic-ruby-agent/pull/3287)
+
 - **Feature: Deprecation notice for the `newrelic deployments` command**
 
   Support for recording deployments using the `newrelic deployments` command is now deprecated and will be removed in agent version 10.0.0. 

lib/boot/strap.rb

@@ -5,8 +5,6 @@
 # This file is designed to bootstrap a `Bundler.require`-based Ruby app (such as
 # a Ruby on Rails app) so the app can be instrumented and observed by the
 # New Relic Ruby agent without the agent being added to the app as a dependency.
-# NOTE: introducing the agent into your application via bootstrap is in beta.
-# Use at your own risk.
 #
 # Given a production-ready Ruby app that optionally has a pre-packaged "frozen"
 # or "deployment"–gem bundle, the New Relic Ruby agent can be introduced