Add Debian 13 support and update Debian 11/12 ISOs

- Add complete Debian 13 (Trixie) support with all necessary configuration files
- Update Debian 11 ISO to 11.11.0 with SHA512 checksum
- Update Debian 12 ISO to 12.12.0 with SHA512 checksum
- Created new debian/13 directory with packer templates and variables
- Added preseed configuration for Debian 13 automated installation

builds/linux/debian/11/linux-debian.pkrvars.hcl.example

@@ -29,8 +29,8 @@ vm_network_card_model   = "virtio"
 
 // Removable Media Settings
 iso_path     = "iso"
-iso_file     = "debian-11.8.0-amd64-netinst.iso"
-iso_checksum = "d7a74813a734083df30c8d35784926deaa36bc41e5c0766388e9f591ab056b72"
+iso_file     = "debian-11.11.0-amd64-netinst.iso"
+iso_checksum = "file:https://get.debian.org/images/archive/11.11.0/amd64/iso-cd/SHA512SUMS"
 
 // Boot Settings
 vm_boot      = "order=virtio0;ide2;net0"