Fix duplicate environment name causes pipeline creation failure

This commit fixes that the duplicate environment name causes
pipeline creation failure.

lib/gitlab/ci/pipeline/seed/deployment.rb

@@ -22,7 +22,7 @@ module Gitlab
             # If there is a validation error on environment creation, such as
             # the name contains invalid character, the job will fall back to a
             # non-environment job.
-            return unless deployment.valid? && deployment.environment.valid?
+            return unless deployment.valid? && deployment.environment.persisted?
 
             deployment.cluster_id =
               deployment.environment.deployment_platform&.cluster_id

lib/gitlab/ci/pipeline/seed/environment.rb

@@ -12,7 +12,7 @@ module Gitlab
           end
 
           def to_resource
-            find_environment || ::Environment.new(attributes)
+            find_environment || ::Environment.create(attributes)
           end
 
           private

spec/lib/gitlab/ci/pipeline/seed/environment_spec.rb

@@ -23,9 +23,9 @@ describe Gitlab::Ci::Pipeline::Seed::Environment do
         }
       end
 
-      it 'returns an environment object' do
+      it 'returns a persisted environment object' do
         expect(subject).to be_a(Environment)
-        expect(subject).not_to be_persisted
+        expect(subject).to be_persisted
         expect(subject.project).to eq(project)
         expect(subject.name).to eq('production')
       end

spec/services/ci/create_pipeline_service_spec.rb

@@ -736,6 +736,28 @@ describe Ci::CreatePipelineService do
       end
     end
 
+    context 'when environment with duplicate names' do
+      let(:ci_yaml) do
+        {
+          deploy: { environment: { name: 'production' }, script: 'ls' },
+          deploy_2: { environment: { name: 'production' }, script: 'ls' }
+        }
+      end
+
+      before do
+        stub_ci_pipeline_yaml_file(YAML.dump(ci_yaml))
+      end
+
+      it 'creates a pipeline with the environment' do
+        result = execute_service
+
+        expect(result).to be_persisted
+        expect(Environment.find_by(name: 'production')).to be_present
+        expect(result.builds.first.deployment).to be_persisted
+        expect(result.builds.first.deployment.deployable).to be_a(Ci::Build)
+      end
+    end
+
     context 'when builds with auto-retries are configured' do
       let(:pipeline)  { execute_service }
       let(:rspec_job) { pipeline.builds.find_by(name: 'rspec') }