Allow downgrades in apt-get simulation

[ikus060]

General information

On Debian, if any package should be downgraded, apt return a single error without listing package to be upgraded. e.g.:

E: Packages were downgraded and -y was used without --allow-downgrades.

You need to pass --allow-downgrades to let apt run the simulation.

Bug reports

Please include:

• Your operating system name and version: Debian Trixie (13)
• Any details about your local setup that might be helpful in troubleshooting: apt-preferences on the system allow downgrading
• Detailed steps to reproduce the bug
• An agent output or SNMP walk
• The ID of a submitted crash report for reference (if applicable)

Proposed changes

• What is the expected behavior? Regaless if any pacakge shoul be downlograded, mk_apt should report the number of pacakge to be upgraded.
• What is the observed behavior? The plugin always returns "No updates pending for installation".

[github-actions]

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[ikus060]

I have read the CLA Document and I hereby sign the CLA or my organization already has a signed CLA.