Disable redis pool because it's already implemented

See merge request https://gitlab.com/gitlab-org/gitlab/-/merge_requests/127741



Merged-by: Mikołaj Wawrzyniak <mwawrzyniak@gitlab.com>
Approved-by: Mikołaj Wawrzyniak <mwawrzyniak@gitlab.com>
Approved-by: Sylvester Chin <schin@gitlab.com>
Reviewed-by: Mikołaj Wawrzyniak <mwawrzyniak@gitlab.com>
Co-authored-by: Patrick Cyiza <jpcyiza@gitlab.com>
Co-authored-by: Igor Drozdov <idrozdov@gitlab.com>