Use latest successful pipeline for default branch

ee/app/models/vulnerability.rb

@@ -74,8 +74,8 @@ class Vulnerability < ApplicationRecord
   end
 
   def resolved_on_default_branch
-    latest_pipeline_for_default_branch = project.pipeline_for(project_default_branch)
+    latest_successful_pipeline_for_default_branch = project.latest_successful_pipeline_for_default_branch
     latest_pipeline_with_vulnerability = finding.pipelines.order(created_at: :desc).first
-    latest_pipeline_with_vulnerability != latest_pipeline_for_default_branch
+    latest_pipeline_with_vulnerability != latest_successful_pipeline_for_default_branch
   end
 end

ee/spec/models/vulnerability_spec.rb

@@ -183,7 +183,7 @@ describe Vulnerability do
 
   describe '#resolved_on_default_branch' do
     let_it_be(:project) { create(:project, :repository, :with_vulnerabilities) }
-    let_it_be(:pipeline_with_vulnerability) { create(:ci_pipeline, project: project, sha: project.commit.id) }
+    let_it_be(:pipeline_with_vulnerability) { create(:ci_pipeline, :success, project: project, sha: project.commit.id) }
     let_it_be(:vulnerability) { project.vulnerabilities.first }
     let_it_be(:finding1) { create(:vulnerabilities_occurrence, vulnerability: vulnerability, pipelines: [pipeline_with_vulnerability]) }
     let_it_be(:finding2) { create(:vulnerabilities_occurrence, vulnerability: vulnerability, pipelines: [pipeline_with_vulnerability]) }
@@ -195,7 +195,11 @@ describe Vulnerability do
     end
 
     context 'Vulnerability::Occurrence is not present on the pipeline for default branch' do
-      let_it_be(:pipeline_without_vulnerability) { create(:ci_pipeline, project: project, sha: project.commit.id) }
+      before do
+        project.instance_variable_set(:@latest_successful_pipeline_for_default_branch, pipeline_without_vulnerability)
+      end
+
+      let_it_be(:pipeline_without_vulnerability) { create(:ci_pipeline, :success, project: project, sha: project.commit.id) }
 
       it { is_expected.to eq(true) }
     end