Don't add pipeline to Vulnerabilities::Finding

Related: https://gitlab.com/gitlab-org/gitlab/-/merge_requests/73115

ee/db/fixtures/development/20_vulnerabilities.rb

@@ -12,14 +12,10 @@ class Gitlab::Seeder::Vulnerabilities
   end
 
   def seed!
-    return unless pipeline
-
     30.times do |rank|
       primary_identifier = create_identifier(rank)
       vulnerability = create_vulnerability
       occurrence = create_occurrence(vulnerability, rank, primary_identifier)
-      # Create finding_pipeline join model
-      occurrence.pipelines << pipeline
       # Create occurrence_identifier join models
       occurrence.identifiers << primary_identifier
       occurrence.identifiers << create_identifier(rank) if rank % 3 == 0
@@ -70,6 +66,7 @@ class Gitlab::Seeder::Vulnerabilities
     scanner = FactoryBot.create(:vulnerabilities_scanner, project: vulnerability.project)
     FactoryBot.create(
       :vulnerabilities_finding,
+      :with_pipeline,
       project: project,
       vulnerability: vulnerability,
       scanner: scanner,

ee/db/fixtures/development/25_downstream_pipelines.rb

@@ -2,7 +2,8 @@
 # EE fixture
 Gitlab::Seeder.quiet do
   Project.not_mass_generated.sample(5).each do |project|
-    project.ci_pipelines.all.sample(2).each do |pipeline|
+    project.builds.sample(2).each do |build|
+      pipeline = build.pipeline
       next if pipeline.source_pipeline
 
       target_pipeline = Ci::Pipeline
@@ -15,7 +16,7 @@ Gitlab::Seeder.quiet do
 
       # link to source pipeline
       pipeline.sourced_pipelines.create!(
-        source_job: pipeline.builds.all.sample,
+        source_job: pipeline.builds.sample,
         source_project: pipeline.project,
         project: target_pipeline.project,
         pipeline: target_pipeline