jellyfin-tui: fix versionCheck on darwin

jellyfin-tui >= v1.2.1 checks data_dir() at startup.
On Darwin, data_dir() = ~/Library/Application Support, so we must ensure
it exists in preInstallCheck.

Refs:
- https://github.com/dhonus/jellyfin-tui/blob/refs/tags/v1.2.1/src/main.rs#L179-185
- https://docs.rs/dirs/latest/dirs/fn.data_dir.html

pkgs/by-name/je/jellyfin-tui/package.nix

@@ -1,5 +1,6 @@
 {
   lib,
+  stdenv,
   fetchFromGitHub,
   rustPlatform,
   pkg-config,
@@ -37,7 +38,9 @@ rustPlatform.buildRustPackage rec {
   versionCheckProgramArg = "--version";
   versionCheckKeepEnvironment = [ "HOME" ];
   preInstallCheck = ''
-    mkdir -p $HOME/.local/share
+    mkdir -p "$HOME/${
+      if stdenv.buildPlatform.isDarwin then "Library/Application Support" else ".local/share"
+    }"
   '';
   doInstallCheck = true;