Fix broken vim php syntax

The loading order (runtimepath) was changed with
cda1f8ae46.
The php syntax loaded as package is now loaded after the neovim native
php syntax file and does not have any effect.

I now remove the package and add the file as XDG config so it is always
loaded first.
This file is not maintained anymore since some years and I still prefer
it over the maintained versions.

home/programs/neovim.nix

@@ -59,16 +59,6 @@ let
     };
   };
 
-  syntax-php = pkgs.vimUtils.buildVimPluginFrom2Nix {
-    name = "syntax-php";
-    src = pkgs.fetchFromGitHub {
-      owner = "StanAngeloff";
-      repo = "php.vim";
-      rev = "2ec2ab9fcc65bfc47c7ba6b3846903528188ceea";
-      sha256 = "lgsaCU6Rzzynkd9SID0chjKaxgEWznrmEl133Syc6cY=";
-    };
-  };
-
   syntax-fluid = pkgs.vimUtils.buildVimPluginFrom2Nix {
     name = "syntax-fluid";
     src = pkgs.fetchFromGitHub {
@@ -242,10 +232,9 @@ in {
     typescript-vim
     syntax-fluid
     vim-twig
-    {
-      plugin = syntax-php;
-      config = builtins.readFile(./neovim/plugins/php.vim);
-    }
+    # PHP Syntax is loaded via xdg config file.
+    # This is necessart as Vim provides a native syntax which would be loaded before the one defined here.
+    # See: https://github.com/NixOS/nixpkgs/commit/cda1f8ae46869c429971323717d622d5b17d9854 where runtimepath is not set.
 
     # Adding features
 

home/xdg.nix

@@ -73,6 +73,8 @@
     "composer/update-channel".text = "stable";
     "composer/auth.json".source = ./files/composer/auth.json;
 
+    "nvim/syntax/php.vim".source = ./files/nvim/syntax/php.vim;
+
   };
 
   dataFile = {