lint: fix typecheck errors

Author: stevearc

lua/oil/util.lua

@@ -582,6 +582,7 @@ M.render_text = function(bufnr, text, opts)
     h_align = "center",
     v_align = "center",
   })
+  ---@cast opts table
   if not vim.api.nvim_buf_is_valid(bufnr) then
     return
   end

lua/oil/view.lua

@@ -871,6 +871,7 @@ M.render_buffer_async = function(bufnr, opts, callback)
   opts = vim.tbl_deep_extend("keep", opts or {}, {
     refetch = true,
   })
+  ---@cast opts table
   if bufnr == 0 then
     bufnr = vim.api.nvim_get_current_buf()
   end