Add Aarch64 Flatpak Build

[istori1]

Description

Screenshot

Issues Fixed or Closed

• Fixes #(issue)

Type of Change

• [ ] Bug fix (non-breaking change which fixes an issue)
• [x] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause existing functionality to not work as expected)

Checklist

• [ ] My code follows the style guidelines of this project
• [ ] I have performed a self-review of my own code
• [ ] I have commented my code, particularly in hard-to-understand areas
• [ ] I have added or updated the docstring/documentation-blocks for new or existing methods/components