Merge branch 'pedropombeiro/rename-runner_fleet' into 'master'

Rename runner_fleet category to fleet_visibility

See merge request !138621



Merged-by: Pedro Pombeiro <noreply@pedro.pombei.ro>
Approved-by: Miguel Rincon <mrincon@gitlab.com>
Approved-by: Eulyeon Ko <5961404-euko@users.noreply.gitlab.com>
Approved-by: Serena Fang <sfang@gitlab.com>
Reviewed-by: Pedro Pombeiro <noreply@pedro.pombei.ro>
Reviewed-by: Eulyeon Ko <5961404-euko@users.noreply.gitlab.com>