Enable ci_workflow_rules_variables by default

changelogs/unreleased/300997-enable-ci_workflow_rules_variables.yml

+---
+title: Implement variables for pipeline workflow rules
+merge_request: 59970
+author:
+type: added

config/feature_flags/development/ci_workflow_rules_variables.yml

@@ -5,4 +5,4 @@ rollout_issue_url: https://gitlab.com/gitlab-org/gitlab/-/issues/300997
 milestone: '13.11'
 type: development
 group: group::pipeline authoring
-default_enabled: false
+default_enabled: true

doc/ci/yaml/README.md

@@ -226,13 +226,15 @@ If your rules match both branch pipelines and merge request pipelines,
 #### `workflow:rules:variables`
 
 > - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/294232) in GitLab 13.11.
-> - It's [deployed behind a feature flag](../../user/feature_flags.md), disabled by default.
-> - It's disabled on GitLab.com.
-> - It's not recommended for production use.
-> - To use it in GitLab self-managed instances, ask a GitLab administrator to [enable it](#enable-or-disable-workflowrulesvariables). **(CORE ONLY)**
+> - [Deployed behind a feature flag](../../user/feature_flags.md), disabled by default.
+> - [Enabled by default](https://gitlab.com/gitlab-org/gitlab/-/issues/300997) in GitLab 13.12.
+> - Enabled on GitLab.com.
+> - Recommended for production use.
+> - For GitLab self-managed instances, GitLab administrators can opt to [disable it](#enable-or-disable-workflowrulesvariables). **(FREE SELF)**
 
-WARNING:
-This feature might not be available to you. Check the **version history** note above for details.
+There can be
+[risks when disabling released features](../../user/feature_flags.md#risks-when-disabling-released-features).
+Refer to this feature's version history for more details.
 
 You can use [`variables`](#variables) in `workflow:rules:` to define variables for specific pipeline conditions.
 
@@ -285,12 +287,12 @@ When the branch is something else:
 - job1's `DEPLOY_VARIABLE` is `job1-default-deploy`.
 - job2's `DEPLOY_VARIABLE` is `default-deploy`.
 
-##### Enable or disable workflow:rules:variables **(CORE ONLY)**
+##### Enable or disable workflow:rules:variables **(FREE SELF)**
 
-rules:variables is under development and not ready for production use.
-It is deployed behind a feature flag that is **disabled by default**.
+workflow:rules:variables is under development but ready for production use.
+It is deployed behind a feature flag that is **enabled by default**.
 [GitLab administrators with access to the GitLab Rails console](../../administration/feature_flags.md)
-can enable it.
+can opt to disable it.
 
 To enable it: