build(docs-infra): do not include `announcements.json` in sitemap (#29754)

The `announcements.json` file should not be included in the sitemap and
including it causes an error in Google Search Console (because the
generated URL does not exist).

(This is a follow-up to fbef94a8e.)

PR Close #29754

aio/tools/transforms/angular-base-package/processors/createSitemap.js

@@ -1,14 +1,15 @@
 module.exports = function createSitemap() {
   return {
     blacklistedDocTypes: [
-      'navigation-json',
+      'announcements-json',
       'contributors-json',
+      'navigation-json',
       'resources-json',
     ],
     blacklistedPaths: [
-      'test',
       'file-not-found',
-      'overview-dump'
+      'overview-dump',
+      'test',
     ],
     $runAfter: ['paths-computed'],
     $runBefore: ['rendering-docs'],