neovim-unwrapped: drop unused fish/nodejs/python from nativeCheckInputs

These were needed for the full `make functionaltest` (provider and
terminal tests, src/clint.py) which has always been disabled because
it is flaky. Since 1d4bf65238 flipped doCheck to true with the
reduced `functionaltest__treesitter` target, they became active build
inputs without being used by any test that actually runs.

Pulling in fish here made its rebuild account grow so much that bumps
would need to go through staging now, which is very unpractical.

Verified that `nix build -f . neovim-unwrapped` still passes the
treesitter checkPhase.

pkgs/by-name/ne/neovim-unwrapped/package.nix

@@ -22,12 +22,6 @@
   nix-update-script,
   writableTmpDirAsHomeHook,
   wasmSupport ? false,
-
-  # now defaults to false because some tests can be flaky (clipboard etc), see
-  # also: https://github.com/neovim/neovim/issues/16233
-  nodejs ? null,
-  fish ? null,
-  python3 ? null,
 }:
 
 let
@@ -194,22 +188,6 @@ stdenv.mkDerivation (
       pkg-config
     ];
 
-    # extra programs test via `make functionaltest`
-    nativeCheckInputs =
-      let
-        pyEnv = python3.withPackages (
-          ps: with ps; [
-            pynvim
-            msgpack
-          ]
-        );
-      in
-      [
-        fish
-        nodejs
-        pyEnv # for src/clint.py
-      ];
-
     postPatch =
       lib.optionalString wasmSupport ''
         substituteInPlace src/nvim/CMakeLists.txt \