virtualboxKvm: use the 7.0.20 patch

The patch seems to be compatible with 7.0.22.

pkgs/applications/virtualization/virtualbox/default.nix

@@ -81,6 +81,7 @@ let
   virtualboxVersion = "7.0.22";
   virtualboxSha256 = "cf3ddf633ca410f1b087b0722413e83247cda4f14d33323dc122a4a42ff61981";
 
+  kvmPatchExpectedVirtualboxVersion = "7.0.20";
   kvmPatchVersion = "20240828";
   kvmPatchHash = "sha256-g0esJbB1IGyLGZMLFJIY8ZYdHWuiM5IZtLMHZvCY6bs=";
 
@@ -106,6 +107,7 @@ stdenv.mkDerivation (finalAttrs: {
     buildType
     virtualboxVersion
     virtualboxSha256
+    kvmPatchExpectedVirtualboxVersion
     kvmPatchVersion
     kvmPatchHash
     virtualboxGuestAdditionsIso
@@ -234,8 +236,8 @@ stdenv.mkDerivation (finalAttrs: {
     # While the KVM patch should not break any other behavior if --with-kvm is not specified,
     # we don't take any chances and only apply it if people actually want to use KVM support.
     ++ optional enableKvm (fetchpatch {
-      name = "virtualbox-${finalAttrs.virtualboxVersion}-kvm-dev-${finalAttrs.kvmPatchVersion}.patch";
-      url = "https://github.com/cyberus-technology/virtualbox-kvm/releases/download/dev-${finalAttrs.kvmPatchVersion}/kvm-backend-${finalAttrs.virtualboxVersion}-dev-${finalAttrs.kvmPatchVersion}.patch";
+      name = "virtualbox-${finalAttrs.kvmPatchExpectedVirtualboxVersion}-kvm-dev-${finalAttrs.kvmPatchVersion}.patch";
+      url = "https://github.com/cyberus-technology/virtualbox-kvm/releases/download/dev-${finalAttrs.kvmPatchVersion}/kvm-backend-${finalAttrs.kvmPatchExpectedVirtualboxVersion}-dev-${finalAttrs.kvmPatchVersion}.patch";
       hash = finalAttrs.kvmPatchHash;
     })
     ++ [