Includes the following fixes:
- Fix cron entry format for clean-up script.
Crontabs in `/etc` should not have a user field. No idea why it used
to work before, but it started giving errors recently:
`/bin/sh: root: not found`.
- Set required env variable in clean-up script. (Broken in cc6f36a9d.)
This was producing the following error:
`ERROR: Missing required environment variable 'AIO_CIRCLE_CI_TOKEN'!`
- Use the correct path for downloads to be removed. (Broken in cc6f36a9d.)
PR Close#25671