fix(treemacs): simplify lsp-treemacs load-order

dec058f fixed the load order between treemacs-nerd-icons and
lsp-treemacs, but lsp-treemacs still loads so late that folks will see a
theme-less Treemacs until they visit their first lsp-mode-enabled file.
This ensures that won't happen.

Amend: dec058fabb
Amend: #7519

modules/ui/treemacs/config.el

@@ -84,6 +84,7 @@ This must be set before `treemacs' has loaded.")
   :after treemacs
   :config (treemacs-set-scope-type 'Perspectives))
 
+
 (use-package! lsp-treemacs
   :when (modulep! +lsp)
-  :after (treemacs lsp))
+  :after treemacs)