Missing dependency for Juju agent installation on Ubuntu minimal

[DUFOUR Olivier]

This was discovered when attempting to bootstrap or add machines within a manual cloud.
While Juju agent is being installed, ultimately the installation will fail due to a chown failing because of a missing user (syslog)

This occurs when :
* bootstraping a controller
* adding a machine and then Juju agent installation will fail
* seen on Ubuntu Jammy 22.04 minimal
* Juju version 3.1 and 3.2

How to reproduce it :
* With LXD spawn a minimal Jammy Ubuntu machine
  (it is possible to follow the steps here https://cloud-images.ubuntu.com/minimal/releases/jammy/release/ :
   * lxc remote add --protocol simplestreams ubuntu-minimal https://cloud-images.ubuntu.com/minimal/releases/
   * lxc launch ubuntu-minimal:jammy
   * make sure you can ssh to the container as ubuntu user
* use juju cli to create a manual cloud with the IP address of the minimal server
  * content of minimal-cloud:
  clouds:
    minimal-cloud:
      type: manual
      endpoint: <email address hidden> (IP of the container)
      regions:
        default: {}

  * $ juju add-cloud minimal-cloud -f ./minimal-cloud.yaml

* attempt to bootstrap the controller to trigger the issue
  * $ juju bootstrap minimal-cloud
Will create the issue seen on the attached file failed-bootstrap.log

Current workaround :
A way to circumvent this issue is simply to make sure that rsyslog package is installed in advance before trying to add a machine or bootstrap with Juju.

[Joseph Phillips (manadart)]

Same issue as https://bugs.launchpad.net/juju/+bug/1895407, though not necessarily the same image.

[Heather Lanigan (hmlanigan)]

Same issue as https://bugs.launchpad.net/juju/+bug/1989168, add-machine rather than bootstrap.