Complete EZP-9254: do not update ezsearch_return_count anymore

This drastically decrease the size of the database for huge sites.

https://jira.ez.no/browse/EZP-9254
Sorry, I was not clear. It also needs the intro section, so in mysql case it should be:
```sql
SET storage_engine=InnoDB;
UPDATE ezsite_data SET value='5.4.0alpha1' WHERE name='ezpublish-version';

DROP TABLE ezsearch_return_count;
```