Add ci_cd_settings delete_all dependency on project

app/models/project.rb

@@ -234,7 +234,7 @@ class Project < ActiveRecord::Base
   has_many :custom_attributes, class_name: 'ProjectCustomAttribute'
 
   has_many :project_badges, class_name: 'ProjectBadge'
-  has_one :ci_cd_settings, class_name: 'ProjectCiCdSetting', inverse_of: :project, autosave: true
+  has_one :ci_cd_settings, class_name: 'ProjectCiCdSetting', inverse_of: :project, autosave: true, dependent: :destroy # rubocop:disable Cop/ActiveRecordDependent
 
   accepts_nested_attributes_for :variables, allow_destroy: true
   accepts_nested_attributes_for :project_feature, update_only: true

changelogs/unreleased/46049-import-export-import-is-broken-due-to-the-addition-of-a-ci-table.yml

@@ -0,0 +1,5 @@
+---
+title: Resolve Import/Export ci_cd_settings error updating the project
+merge_request: 46049
+author:
+type: fixed

spec/models/project_spec.rb

@@ -101,6 +101,14 @@ describe Project do
       end
     end
 
+    context 'updating cd_cd_settings' do
+      it 'does not raise an error' do
+        project = create(:project)
+
+        expect{ project.update(ci_cd_settings: nil) }.not_to raise_exception
+      end
+    end
+
     describe '#members & #requesters' do
       let(:project) { create(:project, :public, :access_requestable) }
       let(:requester) { create(:user) }