Fix Kernel-Clean for Proxmox 8.x

[MickLesk]

✍️ Description

Provide a summary of the changes made and/or reference the issue being addressed.

Add Function for Proxmox 8.3
Support 8.x
Tested on some nodes, worked smooth. userfeedback: work too.

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Please remove unneeded lines!

• Related Issue: Kernel Clean script doesn't remove 4 old (ii) kernels on PVE 8 #551

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🛠️ Type of Change

Please check the relevant options:

• Bug fix (non-breaking change that resolves an issue)
• New feature (non-breaking change that adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change unexpectedly)
• New script (a fully functional and thoroughly tested script or set of scripts)

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✅ Prerequisites

The following steps must be completed for the pull request to be considered:

• Self-review performed (I have reviewed my code to ensure it follows established patterns and conventions.)
• Testing performed (I have thoroughly tested my changes and verified expected functionality.)
• Documentation updated (I have updated any relevant documentation)

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📋 Additional Information (optional)

Provide any extra context or screenshots about the feature or fix here.

[michelroegl-brunner]

LGTM & tested