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/13/linux-debian.pkrvars.hcl.example

@@ -0,0 +1,40 @@
+/*
+    DESCRIPTION:
+    Debian 13 variables used by the Packer Plugin for Proxmox (proxmox-iso).
+*/
+
+// Guest Operating System Metadata
+vm_os_language   = "en_US"
+vm_os_keyboard   = "us"
+vm_os_timezone   = "UTC"
+vm_os_family     = "linux"
+vm_os_name       = "debian"
+vm_os_version    = "13"
+
+// Virtual Machine Guest Operating System Setting
+vm_os_type       = "l26"
+vm_cloudinit     = true
+
+// Virtual Machine Hardware Settings
+vm_bios                 = "ovmf"
+vm_cpu_count            = 1
+vm_cpu_sockets          = 1
+vm_cpu_type             = "kvm64"
+vm_mem_size             = 2048
+vm_disk_type            = "virtio"
+vm_disk_size            = "32G"
+vm_disk_format          = "raw"
+vm_disk_controller_type = "virtio-scsi-pci"
+vm_network_card_model   = "virtio"
+
+// Removable Media Settings
+iso_path     = "iso"
+iso_file     = "debian-13.2.0-amd64-netinst.iso"
+iso_checksum = "file:https://cdimage.debian.org/debian-cd/13.2.0/amd64/iso-cd/SHA512SUMS"
+
+// Boot Settings
+vm_boot      = "order=virtio0;ide2;net0"
+vm_boot_wait = "5s"
+
+// EFI Settings
+vm_firmware_path         = "./OVMF.fd"