message: build: add breakingChangesLabel to merge configuration
  Sets the breakingChangesLabel property to properly confirm breaking changes.
  PR Close
diff: @@ -14,6 +14,7 @@ export const merge: DevInfraMergeConfig['merge'] = async api => {
  mergeReadyLabel: /^action: merge(-assistance)?/,
  caretakerNoteLabel: /^(action: merge-assistance)|(PullApprove: disable)/,
  commitMessageFixupLabel: 'commit message fixup',
  + breakingChangeLabel: 'flag: breaking change',
  // We can pick any of the NPM packages as we are in a monorepo where all packages are
  // published together with the same version and branching.
  labels: await getDefaultTargetLabelConfiguration(api, github, release),
  