Remove FF ci_dependency_variables

So it will be enabled by default for all instances

app/models/concerns/ci/contextable.rb

@@ -18,7 +18,7 @@ module Ci
         variables.concat(deployment_variables(environment: environment))
         variables.concat(yaml_variables)
         variables.concat(user_variables)
-        variables.concat(dependency_variables) if Feature.enabled?(:ci_dependency_variables, project)
+        variables.concat(dependency_variables)
         variables.concat(secret_instance_variables)
         variables.concat(secret_group_variables)
         variables.concat(secret_project_variables(environment: environment))

changelogs/unreleased/217834-remove-FF-ci_dependency_variables.yml

+---
+title: Enable CI Inheriting Env Variables feature
+merge_request: 34495
+author:
+type: added

doc/ci/variables/README.md

@@ -474,8 +474,8 @@ Feature.enable(:instance_variables_ui)
 
 ## Inherit environment variables
 
-> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/22638) in GitLab 13.0.
-> - It's deployed behind a feature flag (`ci_dependency_variables`), disabled by default.
+> - [Introduced](https://gitlab.com/gitlab-org/gitlab/-/issues/22638) in GitLab 13.0 behind a disabled [feature flag](../../administration/feature_flags.md): `ci_dependency_variables`.
+> - [Feature flag removed](https://gitlab.com/gitlab-org/gitlab/-/issues/217834) in GitLab 13.1.
 
 You can inherit environment variables from dependent jobs.
 
@@ -520,25 +520,6 @@ deploy:
       artifacts: true
 ```
 
-### Enable inherited environment variables **(CORE ONLY)**
-
-The Inherited Environment Variables feature is under development and not ready for production use. It is
-deployed behind a feature flag that is **disabled by default**.
-[GitLab administrators with access to the GitLab Rails console](../../administration/feature_flags.md)
-can enable it for your instance.
-
-To enable it:
-
-```ruby
-Feature.enable(:ci_dependency_variables)
-```
-
-To disable it:
-
-```ruby
-Feature.disable(:ci_dependency_variables)
-```
-
 ## Priority of environment variables
 
 Variables of different types can take precedence over other

spec/models/ci/build_spec.rb

@@ -3123,24 +3123,8 @@ describe Ci::Build do
 
       let!(:job_variable) { create(:ci_job_variable, :dotenv_source, job: prepare) }
 
-      context 'FF ci_dependency_variables is enabled' do
-        before do
-          stub_feature_flags(ci_dependency_variables: true)
-        end
-
-        it 'inherits dependent variables' do
-          expect(build.scoped_variables.to_hash).to include(job_variable.key => job_variable.value)
-        end
-      end
-
-      context 'FF ci_dependency_variables is disabled' do
-        before do
-          stub_feature_flags(ci_dependency_variables: false)
-        end
-
-        it 'does not inherit dependent variables' do
-          expect(build.scoped_variables.to_hash).not_to include(job_variable.key => job_variable.value)
-        end
+      it 'inherits dependent variables' do
+        expect(build.scoped_variables.to_hash).to include(job_variable.key => job_variable.value)
       end
     end
   end