inkscape: fix build against upcoming gcc-12

Without the change build fails as:

    src/io/file.h:29:63: error: use of deleted function
      'std::__cxx11::basic_string<...>::basic_string(std::nullptr_t) [...]'
       29 | SPDocument* ink_file_new(const std::string &Template = nullptr);
          |                                                               ^

pkgs/applications/graphics/inkscape/default.nix

@@ -88,7 +88,13 @@ stdenv.mkDerivation rec {
       url = "https://gitlab.com/inkscape/inkscape/-/commit/b3dabef2245d4e4e977ee9d6776be9a134493515.patch";
       sha256 = "YhqUlRBKL1vJ/iCM/DvdwbmPIsAHQpcgf4TPpjlnBng=";
     })
-
+    # Fix build against gcc-12
+    # https://gitlab.com/inkscape/inkscape/-/merge_requests/3683
+    (fetchpatch {
+      name = "gcc-12.patch";
+      url = "https://gitlab.com/inkscape/inkscape/-/commit/3825abc637ac2d3bc6ff997503b0631ac14e16b5.patch";
+      sha256 = "sha256-VzKrWCkcVA1Co/xBTyh28Zhm2zFE/2jfZ3LveK0raO4=";
+    })
   ];
 
   postPatch = ''