samples: example for legacy boot but gpt partition

An example demonstrating the use of the BIOS boot partition to
enable legacy grub2 boot (i.e. non-efi boot) with a GPT partition
layout.

samples/f30-qcow2-gpt.json

@@ -0,0 +1,99 @@
+{
+  "stages": [
+    {
+      "name": "org.osbuild.dnf",
+      "options": {
+        "releasever": "30",
+        "basearch": "x86_64",
+        "install_weak_deps": true,
+        "repos": [
+            "sha256:9f596e18f585bee30ac41c11fb11a83ed6b11d5b341c1cb56ca4015d7717cb97"
+        ],
+        "packages": [
+          "@Fedora Cloud Server",
+          "chrony",
+          "kernel",
+          "selinux-policy-targeted",
+          "grub2-pc",
+          "spice-vdagent",
+          "qemu-guest-agent",
+          "xen-libs",
+          "langpacks-en"
+        ],
+        "exclude_packages": [
+          "dracut-config-rescue"
+        ]
+      }
+    },
+    {
+      "name": "org.osbuild.systemd",
+      "options": {
+        "enabled_services": [
+          "cloud-config",
+          "cloud-final",
+          "cloud-init",
+          "cloud-init-local"]
+      }
+    },
+    {
+      "name": "org.osbuild.locale",
+      "options": {
+        "language": "en_US"
+      }
+    },
+    {
+      "name": "org.osbuild.fstab",
+      "options": {
+        "filesystems": [
+          {
+            "uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
+            "vfs_type": "ext4",
+            "path": "/",
+            "freq": "1",
+            "passno": "1"
+          }
+        ]
+      }
+    },
+    {
+      "name": "org.osbuild.grub2",
+      "options": {
+        "root_fs_uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
+        "kernel_opts": "ro biosdevname=0 net.ifnames=0"
+      }
+    },
+    {
+      "name": "org.osbuild.selinux",
+      "options": {
+        "file_contexts": "etc/selinux/targeted/contexts/files/file_contexts"
+      }
+    },
+    {
+      "name": "org.osbuild.fix-bls"
+    }
+  ],
+  "assembler":
+    {
+      "name": "org.osbuild.qemu",
+      "options": {
+        "format": "qcow2",
+        "filename": "base.qcow2",
+        "ptuuid": "29579f67-d390-43e7-bd96-dc8f5461171e",
+        "pttype": "gpt",
+        "partitions": [
+          {
+            "size": 8192, "type": "21686148-6449-6E6F-744E-656564454649", "bootable": true
+          },
+          {
+            "type": "0FC63DAF-8483-4772-8E79-3D69D8477DE4",
+            "filesystem": {
+              "type": "ext4",
+              "uuid": "76a22bf4-f153-4541-b6c7-0332c0dfaeac",
+              "mountpoint": "/"
+            }
+          }
+        ],
+        "size": 3221225472
+      }
+    }
+}