perf(extras): never load nested extras

lua/lazyvim/util/plugin.lua

@@ -111,15 +111,40 @@ function M.fix_imports()
       )
       spec.import = rename
     end
-    local dep = M.deprecated_extras[spec and spec.import]
+    local dep = M.deprecated_extras[spec.import]
     if dep then
       dep = dep .. "\n" .. "Please remove the extra from `lazyvim.json` to hide this warning."
       LazyVim.warn(dep, { title = "LazyVim", once = true, stacktrace = true, stacklevel = 6 })
       return false
     end
+
+    local modname = spec.import
+    if type(modname) == "string" and vim.startswith(modname, "lazyvim.plugins.extras.") then
+      M.single_import(spec)
+    end
   end)
 end
 
+---@param spec LazySpecImport
+function M.single_import(spec)
+  local modname = spec.import
+  if type(modname) ~= "string" then
+    return
+  end
+  spec.name = modname
+  spec.import = function()
+    package.loaded[modname] = nil
+    local ok, mod, foo = pcall(require, modname) ---@type boolean, table?, unknown
+    if ok and type(mod) == "table" then
+      if foo then
+        return nil, "Spec module returned more than one value. Expected a single value."
+      end
+      return mod
+    end
+    return nil, mod
+  end
+end
+
 function M.fix_renames()
   ---@param plugin LazyPluginSpec
   Meta.add = LazyVim.inject.args(Meta.add, function(self, plugin)