fix(retail): add region tag for node.js - Update purge user events (#4129)

* Update search-simple-query.js

Added region tag to simply search query for code snippet update in the documentation.

* Update search-with-pagination.js

* Update purge-user-events.js

* Apply suggestions from robot code review

Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

---------

Co-authored-by: Katie McLaughlin <[email protected]>
Co-authored-by: gemini-code-assist[bot] <176961590+gemini-code-assist[bot]@users.noreply.github.com>

Author: 3 people

retail/interactive-tutorials/events/purge-user-events.js

@@ -11,6 +11,7 @@
 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 // See the License for the specific language governing permissions and
 // limitations under the License.
+// [START retail_purge_user_events]
 
 'use strict';
 
@@ -68,3 +69,4 @@ process.on('unhandledRejection', err => {
 });
 
 main();
+// [END retail_purge_user_events]