fleet/changes/17308-script-content-cleanup

- Adds a migration that removes the `script_contents` columns that aren't needed anymore due to the
  introduction of the `script_contents` table
- Adds a cleanup cron job that will remove unused script contents periodically
feat: script content cleanup and column removal (#17374) > Related issue: #17374 # Checklist for submitter If some of the following don't apply, delete the relevant line. <!-- Note that API documentation changes are now addressed by the product design team. --> - [x] Changes file added for user-visible changes in `changes/` or `orbit/changes/`. See [Changes files](https://fleetdm.com/docs/contributing/committing-changes#changes-files) for more information. - [x] Input data is properly validated, `SELECT *` is avoided, SQL injection is prevented (using placeholders for values in statements) - [x] Added/updated tests - [x] If database migrations are included, checked table schema to confirm autoupdate - For database migrations: - [x] Checked schema for all modified table for columns that will auto-update timestamps during migration. - [x] Confirmed that updating the timestamps is acceptable, and will not cause unwanted side effects. - [x] Manual QA for all new/changed functionality 2024-03-13 19:53:08 +00:00			- Adds a migration that removes the `script_contents` columns that aren't needed anymore due to the
			introduction of the `script_contents` table
			`- Adds a cleanup cron job that will remove unused script contents periodically`