Remove feature flag create_cloud_run_clusters

This flag has been enabled by default since 12.5, the removal of the
flag is just a formality.

Changelog: changed

app/views/clusters/clusters/gcp/_form.html.haml

@@ -62,7 +62,6 @@
       %p.form-text.text-muted
         = s_('ClusterIntegration|Learn more about %{help_link_start_machine_type}machine types%{help_link_end} and %{help_link_start_pricing}pricing%{help_link_end}.').html_safe % { help_link_start_machine_type: help_link_start % { url: machine_type_link_url }, help_link_start_pricing: help_link_start % { url: pricing_link_url }, help_link_end: help_link_end }
 
-    - if Feature.enabled?(:create_cloud_run_clusters, clusterable, default_enabled: true)
     .form-group
       = provider_gcp_field.check_box :cloud_run, { label: s_('ClusterIntegration|Enable Cloud Run for Anthos'),
         label_class: 'label-bold' }

config/feature_flags/development/create_cloud_run_clusters.yml

----
-name: create_cloud_run_clusters
-introduced_by_url: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/19063
-rollout_issue_url: 
-milestone: '12.5'
-type: development
-group: group::configure
-default_enabled: true

spec/views/projects/clusters/clusters/gcp/_form.html.haml_spec.rb

@@ -23,16 +23,4 @@ RSpec.describe 'clusters/clusters/gcp/_form' do
       expect(rendered).to have_selector("input[id='cluster_provider_gcp_attributes_cloud_run']")
     end
   end
-
-  context 'with cloud run feature flag disabled' do
-    before do
-      stub_feature_flags(create_cloud_run_clusters: false)
-    end
-
-    it 'does not have a cloud run checkbox' do
-      render
-
-      expect(rendered).not_to have_selector("input[id='cluster_provider_gcp_attributes_cloud_run']")
-    end
-  end
 end