Meta: Alphabetize IDL files in the GN build

Meta/gn/secondary/Userland/Libraries/LibWeb/idl_files.gni

@@ -23,8 +23,8 @@ standard_idl_files = [
   "//Userland/Libraries/LibWeb/Animations/AnimationEffect.idl",
   "//Userland/Libraries/LibWeb/Animations/AnimationPlaybackEvent.idl",
   "//Userland/Libraries/LibWeb/Animations/AnimationTimeline.idl",
-  "//Userland/Libraries/LibWeb/Animations/KeyframeEffect.idl",
   "//Userland/Libraries/LibWeb/Animations/DocumentTimeline.idl",
+  "//Userland/Libraries/LibWeb/Animations/KeyframeEffect.idl",
   "//Userland/Libraries/LibWeb/Clipboard/Clipboard.idl",
   "//Userland/Libraries/LibWeb/Crypto/Crypto.idl",
   "//Userland/Libraries/LibWeb/Crypto/CryptoKey.idl",