feat(extras): added extra for snacks picker (#5368)

## Description

See https://github.com/folke/snacks.nvim/pull/445

NOTE: I'm **not** going to replace `fzf-lua` anytime soon. Learned my
lessons with that one :)

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## Checklist

- [x] I've read the
[CONTRIBUTING](https://github.com/LazyVim/LazyVim/blob/main/CONTRIBUTING.md)
guidelines.

lua/lazyvim/util/pick.lua

@@ -42,11 +42,13 @@ function M.register(picker)
   return true
 end
 
----@return "telescope" | "fzf"
+---@return "telescope" | "fzf" | "snacks"
 function M.want()
   vim.g.lazyvim_picker = vim.g.lazyvim_picker or "auto"
   if vim.g.lazyvim_picker == "auto" then
-    return LazyVim.has_extra("editor.telescope") and "telescope" or "fzf"
+    return LazyVim.has_extra("editor.snacks_picker") and "snacks"
+      or LazyVim.has_extra("editor.telescope") and "telescope"
+      or "fzf"
   end
   return vim.g.lazyvim_picker
 end