build: remove presubmit dependency on luvit-meta

As discussed in https://github.com/yetone/avante.nvim/pull/2536 the
project should either use luv bindings from luals or luvit-meta
library, but not both, as they conflict with each other (especially
with uv.uv_timer_t). Given that other projects such as kickstart.nvim
and lazydev.nvim are switching to use the former, we should do the same
and drop luvit-meta dependency.

Also adjust code that was using luvit-meta's annotations for timers.

lua/avante/suggestion.lua

@@ -30,7 +30,7 @@ local SUGGESTION_NS = api.nvim_create_namespace("avante_suggestion")
 ---@field augroup integer
 ---@field ignore_patterns table
 ---@field negate_patterns table
----@field _timer? uv.uv_timer_t | uv_timer_t
+---@field _timer? uv.uv_timer_t
 ---@field _contexts table
 ---@field is_on_throttle boolean
 local Suggestion = {}