Fix backported CE code

app/models/environment.rb

@@ -241,9 +241,9 @@ class Environment < ActiveRecord::Base
   end
 
   def cluster_prometheus_adapter
-    return unless project.deployment_platform.respond_to?(:cluster)
+    return unless deployment_platform.respond_to?(:cluster)
 
-    cluster = project.deployment_platform.cluster
+    cluster = deployment_platform.cluster
     return unless cluster.application_prometheus&.installed?
 
     cluster.application_prometheus

spec/models/environment_spec.rb

@@ -493,8 +493,8 @@ describe Environment do
       end
 
       it 'returns the metrics from the deployment service' do
-        expect(project.monitoring_service)
-          .to receive(:environment_metrics).with(environment)
+        expect(environment.prometheus_adapter)
+          .to receive(:query).with(:environment, environment)
                 .and_return(:fake_metrics)
 
         is_expected.to eq(:fake_metrics)