fix: incorrect function signature

Author: sm-victorw

lua/supermaven-nvim/textual.lua

@@ -246,7 +246,7 @@ function M.derive_completion(completion, params)
       if u.trim(output) ~= "" then
         return force_complete(output, dedent, params, completion_index)
       end
-      local following_line = params.get_following_line(output)
+      local following_line = params.get_following_line(#delete_lines)
       if u.trim_end(response_item.verify) == u.trim_end(following_line) then
         delete_lines[#delete_lines + 1] = following_line
       end

lua/supermaven-nvim/types.lua

@@ -39,7 +39,7 @@
 ---@class CompletionParams
 ---@field line_before_cursor string
 ---@field line_after_cursor string
----@field get_following_line fun(line: string): string
+---@field get_following_line fun(index: integer): string
 ---@field dust_strings string[]
 ---@field can_show_partial_line boolean
 ---@field can_retry boolean