feat(edk2): disable Xen OVMF build variant

Azure Linux targets Hyper-V/KVM, not Xen. The upstream edk2 spec builds
a Xen OVMF firmware variant (edk2-ovmf-xen) when %fedora is defined.

Disable by renaming [build.ovmf.xen] in edk2-build.fedora so the build
script skips the Xen target, and remove the ovmf-xen subpackage via
spec-remove-section overlays.

All other Fedora-path features (IGVM, 4M qcow2, experimental, riscv64,
loongarch64, ext4, tools-python) are preserved.

Verified: build succeeds, edk2-ovmf-xen RPM is no longer produced,
main edk2-ovmf package is intact.

Author: christopherco

base/comps/components.toml

@@ -414,7 +414,6 @@ includes = ["**/*.comp.toml", "component-check-disablement.toml"]
 [components.ed]
 [components.ed25519-java]
 [components.editorconfig]
-[components.edk2]
 [components.efi-rpm-macros]
 [components.efibootmgr]
 [components.efitools]

base/comps/edk2/edk2.comp.toml

@@ -0,0 +1,31 @@
+[components.edk2]
+
+# Disable the Xen OVMF build variant — not applicable to Azure Linux (Hyper-V/KVM).
+
+# 1. Rename the build config section so edk2-build.py skips the Xen build.
+#    The script iterates sections starting with "build." prefix.
+[[components.edk2.overlays]]
+description = "Disable Xen OVMF build - rename config section so edk2-build.py skips it"
+type = "file-search-replace"
+file = "edk2-build.fedora"
+regex = '\[build\.ovmf\.xen\]'
+replacement = '[disabled.ovmf.xen]'
+
+# 2. Remove the ovmf-xen subpackage entirely.
+[[components.edk2.overlays]]
+description = "Remove %package ovmf-xen"
+type = "spec-remove-section"
+section = "%package"
+package = "ovmf-xen"
+
+[[components.edk2.overlays]]
+description = "Remove %description ovmf-xen"
+type = "spec-remove-section"
+section = "%description"
+package = "ovmf-xen"
+
+[[components.edk2.overlays]]
+description = "Remove %files ovmf-xen"
+type = "spec-remove-section"
+section = "%files"
+package = "ovmf-xen"