Revert "vimPlugins.nvim-treesitter: collate grammars"

This reverts PR #319233. It caused a lot of weird regressions and a lot
of headaches for me. Even a 20% improvement isn't worth it.

Also see https://github.com/NixOS/nixpkgs/pull/319233#issuecomment-2339271761

pkgs/applications/editors/vim/plugins/nvim-treesitter/overrides.nix

@@ -36,22 +36,8 @@ let
   # pkgs.vimPlugins.nvim-treesitter.withAllGrammars
   withPlugins =
     f: self.nvim-treesitter.overrideAttrs {
-      passthru.dependencies =
-        let
-          grammars = map grammarToPlugin
+      passthru.dependencies = map grammarToPlugin
         (f (tree-sitter.builtGrammars // builtGrammars));
-          copyGrammar = grammar:
-            let name = lib.last (lib.splitString "-" grammar.name); in
-            "ln -sf ${grammar}/parser/${name}.so $out/parser/${name}.so";
-        in
-        [
-          (runCommand "vimplugin-treesitter-grammars"
-            { meta.platforms = lib.platforms.all; }
-            ''
-              mkdir -p $out/parser
-              ${lib.concatMapStringsSep "\n" copyGrammar grammars}
-            '')
-        ];
     };
 
   withAllGrammars = withPlugins (_: allGrammars);