Revert "Merge branch 'mc/bug/fail-upstream-on-invalid-yaml' into 'master'"

This reverts commit 043a8dd7, reversing
changes made to 6fd55c2c.

app/services/ci/create_cross_project_pipeline_service.rb

@@ -18,7 +18,7 @@ module Ci
         current_user,
         pipeline_params.fetch(:target_revision))
 
-      downstream_pipeline = service.execute(
+      service.execute(
         pipeline_params.fetch(:source), pipeline_params[:execute_params]) do |pipeline|
           @bridge.sourced_pipelines.build(
             source_pipeline: @bridge.pipeline,
@@ -28,10 +28,6 @@ module Ci
 
           pipeline.variables.build(@bridge.downstream_variables)
         end
-
-      downstream_pipeline.tap do |pipeline|
-        @bridge.drop!(:downstream_pipeline_creation_failed) if pipeline.has_yaml_errors?
-      end
     end
 
     private

changelogs/unreleased/mc-bug-fail-upstream-on-invalid-yaml.yml

----
-title: Fail upstream bridge on downstream pipeline creation failure.
-merge_request: 24092
-author:
-type: fixed

spec/services/ci/create_cross_project_pipeline_service_spec.rb

@@ -267,34 +267,6 @@ describe Ci::CreateCrossProjectPipelineService, '#execute' do
       end
     end
 
-    context 'when downstream pipeline creation errors out' do
-      let(:stub_config) { false }
-
-      before do
-        stub_ci_pipeline_yaml_file(YAML.dump(invalid: { yaml: 'error' }))
-      end
-
-      it 'creates only one new pipeline' do
-        expect { service.execute(bridge) }
-          .to change { Ci::Pipeline.count }.by(1)
-      end
-
-      it 'creates a new pipeline in the downstream project' do
-        pipeline = service.execute(bridge)
-
-        expect(pipeline.user).to eq bridge.user
-        expect(pipeline.project).to eq downstream_project
-      end
-
-      it 'drops the bridge' do
-        pipeline = service.execute(bridge)
-
-        expect(pipeline.reload).to be_failed
-        expect(bridge.reload).to be_failed
-        expect(bridge.failure_reason).to eq('downstream_pipeline_creation_failed')
-      end
-    end
-
     context 'when bridge job has YAML variables defined' do
       before do
         bridge.yaml_variables = [{ key: 'BRIDGE', value: 'var', public: true }]