Scripts in /var/lib/cloud/scripts/vendor are never run

# Bug report
I was looking at using vendor scripts as another place to drop in scripts to run. It doesn't look like these actually ever get run? I also see that cc_vendor_scripts use the current instance path. But this is a symlink to a path with the launched instance ID so it doesn't seem possible to include a script in there. Is there a way to use vendor scripts then in AWS with EC2?

I was trying to provide a set of scripts to run on boot that wouldn't collide with other user scripts.

## Steps to reproduce the problem
Put a script in `/var/lib/cloud/scripts/vendor`

## Environment details
- Cloud-init version:
- Operating System Distribution: Ubuntu 24.04
- Cloud provider, platform or installer type: AWS EC2