remove deprecated sign-set func

lua/plugin/lspconfig.lua

@@ -16,11 +16,6 @@ return {
         -- enable completion triggered by <c-x><c-o>
         vim.api.nvim_buf_set_option(bufnr, 'omnifunc', 'v:lua.vim.lsp.omnifunc')
       end
-      local signs = { Error = "󰈸 ", Warn = " ", Hint = "󰌶 ", Info = " " }
-      for type, icon in pairs(signs) do
-        local hl = "DiagnosticSign" .. type
-        vim.fn.sign_define(hl, { text = icon, texthl = hl })
-      end
 
       local border = {
         { "╭", "FloatBorder" },
@@ -34,6 +29,7 @@ return {
       }
 
       vim.diagnostic.config({
+        signs = { text = { [vim.diagnostic.severity.ERROR] = "✘ ", [vim.diagnostic.severity.WARN] = " ", [vim.diagnostic.severity.HINT] = " ", [vim.diagnostic.severity.INFO] = " " } },
         float = { border = border },
         virtual_text = {
           prefix = '●', -- Could be '●', '■', 'x', '▎', or anything else