message: build: update dev-infra merge configuration
  Merge configuration no longer accepts custom labels, in order to achieve consistent labelling as specified in the Angular versioning/branching/labelling spec.
diff: -import { DevInfraMergeConfig } from '@angular/dev-infra-private/ng-dev/pr/merge/config';
  -import { getDefaultTargetLabelConfiguration } from '@angular/dev-infra-private/ng-dev/pr/merge/defaults';
  -import { github } from './github';
  -import { release } from './release';
  +import { MergeConfig } from '@angular/dev-infra-private/ng-dev/pr/merge/config';
  /**
  * Configuration for the merge tool in `ng-dev`. This sets up the labels which
  * are respected by the merge script (e.g. the target labels).
  */
  -export const merge: DevInfraMergeConfig['merge'] = async (api) => {
  - return {
  +export const merge: MergeConfig = {
  githubApiMerge: {
  default: 'rebase',
  labels: [{ pattern: 'squash commits', method: 'squash' }],
  @@ -17,8 +13,4 @@ export const merge: DevInfraMergeConfig['merge'] = async (api) => {
  mergeReadyLabel: /^action: merge(-assistance)?/,
  caretakerNoteLabel: /(action: merge-assistance)/,
  commitMessageFixupLabel: 'commit message fixup',
  - // 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),
  - };
  };
  