Remove beta note for Configuration variables

This beta note was out of date. It was added in 4717018 (Jan 2023) and the feature was announced as stable [in July 2023](https://github.blog/enterprise-software/devops/introducing-required-workflows-and-configuration-variables-to-github-actions/).

c7404ec (Dec 2024) removed the beta note from “Defining configuration variables for multiple workflows”. This commit cleans up the last remaining usage, and the shared beta note file itself.

Author: adamchainz

content/actions/writing-workflows/choosing-what-your-workflow-does/accessing-contextual-information-about-workflow-runs.md

@@ -347,8 +347,6 @@ jobs:
 
 ## `vars` context
 
-{% data reusables.actions.configuration-variables-beta-note %}
-
 The `vars` context contains custom configuration variables set at the organization, repository, and environment levels. For more information about defining configuration variables for use in multiple workflows, see [AUTOTITLE](/actions/learn-github-actions/variables#defining-variables-for-multiple-workflows).
 
 ### Example contents of the `vars` context