assimp: fix build with gcc15

- add patch from merged upstream PR:
https://www.github.com/assimp/assimp/pull/6283

Fixes build failure with gcc15:
```
/build/source/code/AssetLib/X3D/X3DGeoHelper.cpp: In static member
function 'static void Assimp::X3DGeoHelper::coordIdx_str2lines_arr(const std::vector<int>&, std::vector<aiFace>&)':
/build/source/code/AssetLib/X3D/X3DGeoHelper.cpp:194:20: error: array
subscript -1 is outside array bounds of 'int [2305843009213693951]' [-Werror=array-bounds=]
  194 |     if (f_data.back() != (-1)) {
      |         ~~~~~~~~~~~^~
In file included from /nix/store/9jzssiinw6a2dib6k3hzd48j6ywck4iw-gcc-15.2.0/include/c++/15.2.0/x86_64-unknown-linux-gnu/bits/c++allocator.h:33,
                 from /nix/store/9jzssiinw6a2dib6k3hzd48j6ywck4iw-gcc-15.2.0/include/c++/15.2.0/bits/allocator.h:46,
                 from /nix/store/9jzssiinw6a2dib6k3hzd48j6ywck4iw-gcc-15.2.0/include/c++/15.2.0/string:45,
                 from /build/source/include/assimp/types.h:78,
                 from /build/source/code/AssetLib/X3D/X3DGeoHelper.h:6,
                 from /build/source/code/AssetLib/X3D/X3DGeoHelper.cpp:1:
```

pkgs/by-name/as/assimp/package.nix

@@ -2,6 +2,7 @@
   lib,
   stdenv,
   fetchFromGitHub,
+  fetchpatch,
   cmake,
   zlib,
   nix-update-script,
@@ -23,6 +24,16 @@ stdenv.mkDerivation (finalAttrs: {
     hash = "sha256-ixtqK+3iiL17GEbEVHz5S6+gJDDQP7bVuSfRMJMGEOY=";
   };
 
+  patches = [
+    # Fix build with gcc15
+    # https://github.com/assimp/assimp/pull/6283
+    (fetchpatch {
+      name = "assimp-fix-invalid-vector-gcc15.patch";
+      url = "https://github.com/assimp/assimp/commit/59bc03d931270b6354690512d0c881eec8b97678.patch";
+      hash = "sha256-O+JPwcOdyFtmFE7eZojHo1DUavF5EhLYlUyxtYo/KF4=";
+    })
+  ];
+
   nativeBuildInputs = [ cmake ];
 
   buildInputs = [