Adjust online GC settings for GitLab.com

Context

Followup from 2024-04-05: RegistryServiceDatabaseApdexSLOViol... (gitlab-com/gl-infra/production#17785 - closed). See this thread for more details.

Task

Adjust online GC workers run internals, which currently sit at 2s and 500ms for manifest and blob workers, respectively. We likely can bump the blob internal to 1s, there doesn't seem to be the need to keep it this low.