Update category for table ci_cost_settings
What does this MR do and why?
The Compute Minutes feature set was moved from Pipeline Execution to the Hosted Runner team previously. The ci_cost_settings table is listed as being part of the Continuous Integration category but is used for Compute Minutes. As such, I am updating the category in the docs to hosted_runner, which seems to be the category used on at least some of the Compute Minute issues now.