fix(lsp): remove unnecessary config field

after/lsp/xml_ls.lua

@@ -1,5 +1,3 @@
-local lsp = require("lsp")
-
 ---@type vim.lsp.Config
 return {
     cmd = {
@@ -7,7 +5,6 @@ return {
     },
     filetypes = { "xml" },
     root_markers = { ".git" },
-    on_attach = lsp.on_attach,
     init_options = {
         logLevel = "warning",
         numWorkers = 4,