tilix: fix build issue with ldc 1.31+

pkgs/applications/terminal-emulators/tilix/default.nix

···
 , libunwind
 , appstream
 , nixosTests
+, fetchpatch
 }:
 
 stdenv.mkDerivation rec {
···
     gtkd
     libsecret
     libunwind
+  ];
+
+  patches = [
+    # https://github.com/gnunn1/tilix/issues/2151
+    (fetchpatch {
+      name = "tilix-replace-std-xml-with-gmarkup.patch";
+      url = "https://github.com/gnunn1/tilix/commit/b02779737997a02b98b690e6f8478d28d5e931a5.patch";
+      hash = "sha256-6p+DomJEZ/hCW8RTjttKsTDsgHZ6eFKj/71TU5O/Ysg=";
+    })
   ];
 
   postPatch = ''