Set artifact working directory to be in the destination store to prevent unnecessary I/O

Similar to #33218 (closed), build artifacts were being uploaded into a CarrierWave temporary directory in the Rails root directory before moved to their final destination, which could cause a copy across filesystems. This merge request refactors the work in !11866 (merged) so that any uploader can just override work_dir to change the default implementation.

Closes #33274 (closed)