build(aio): fail the doc-gen if the nav is invalid (#23175)

PR Close #23175

aio/tools/transforms/angular.io-package/processors/processNavigationMap.js

@@ -21,7 +21,7 @@ module.exports = function processNavigationMap(versionInfo, log) {
         log.error(`Navigation doc: ${navigationDoc.fileInfo.relativePath} contains invalid urls`);
         // eslint-disable-next-line no-console
         console.log(errors);
-        // TODO(petebd): fail if there are errors: throw new Error('processNavigationMap failed');
+        throw new Error('processNavigationMap failed');
       }
 
       // Add in the version data in a "secret" field to be extracted in the docs app