Draft: Fix flaky test: default S3 uploader values make code fail

See comment #2860 (comment 91829)

Some tests seem to fail when doing --stale. The reason is that the code that is tested indirectly make use of the uploader. When they failed, it's because the uploader was set to S3 whose default settings don't work properly. For the tests/modules that failed, I started with setting the global settings to the Local uploader who does work. I have no idea why I only see these failures when running with --stale.