Fix pipeline findings query

ee/app/assets/javascripts/security_dashboard/graphql/queries/pipeline_findings.query.graphql

@@ -13,6 +13,7 @@ query pipelineFindings(
 ) {
   project(fullPath: $fullPath) {
     pipeline(iid: $pipelineId) {
+      id
       securityReportFindings(
         after: $after
         first: $first

ee/spec/frontend/security_dashboard/mock_data/index.js

@@ -248,6 +248,7 @@ export const mockPipelineFindingsResponse = ({ hasNextPage } = {}) => ({
   data: {
     project: {
       pipeline: {
+        id: 'gid://gitlab/Ci::Pipeline/59',
         securityReportFindings: {
           nodes: [
             {