feat: Add --dry-run and --no-async flags to update_content_metadata job

[marlonkeating]

Description

Adds a couple flags to the update_content_metadata job

--dry-run: Don't commit changes to the database, just log them --no-async: Don't spin off sub-tasks into separate threads, to allow for easier local logging

Ticket Link

ENT-8602

Post-review

• [ ] Squash commits into discrete sets of changes
• [ ] Ensure that once the changes have been deployed to stage, prod is manually deployed