nixos/tabby: fix typo (#355223)

Author: Aleksanaa

nixos/modules/services/misc/tabby.nix

@@ -34,7 +34,7 @@ in
           If you want to utilize an existing model that you've already
           downloaded you'll need to move it into tabby's state directory which
           lives in `/var/lib/tabby`. Because the tabby.service is configured to
-          use a DyanmicUser the service will need to have been started at least
+          use a DynamicUser the service will need to have been started at least
           once before you can move the locally existing model into
           `/var/lib/tabby`. You can set the model to 'none' and tabby will
           startup and fail to download a model, but will have created the