fix(docs-infra): exit with an error when cleaning up the preview server fails (#36837)

Previously, when the preview server `build-cleanup` script failed, the
error was logged but not reflected to the commands exit code. This seems
to have been accidentally broken in #23576.

This commit fixes it by ensuring the error is re-thrown from the
`BuildCleaner#cleanUp()` method to allow the process to exit with an
error exit code.

PR Close #36837

aio/aio-builds-setup/dockerbuild/scripts-js/lib/clean-up/build-cleaner.ts

@@ -35,6 +35,7 @@ export class BuildCleaner {
       ]);
     } catch (error) {
       this.logger.error('ERROR:', error);
+      throw error;
     }
   }