Remove gitaly NamespaceService from tests
What does this MR do and why?
NamespaceService was removed from gitaly in %16.7 (gitaly!6292 (merged))
This MR updates the tests to use a different method to delete the repository if it exists.
This will allow the project to be upgraded to gitaly 16.7 eventually
How to set up and validate locally
Run the tests
Edited by Terri Chu