perf(illuminate): on large files >2000 lines, enable lsp references only

lua/lazyvim/plugins/editor.lua

@@ -303,7 +303,13 @@ return {
   {
     "RRethy/vim-illuminate",
     event = { "BufReadPost", "BufNewFile" },
-    opts = { delay = 200 },
+    opts = {
+      delay = 200,
+      large_file_cutoff = 2000,
+      large_file_overrides = {
+        providers = { "lsp" },
+      },
+    },
     config = function(_, opts)
       require("illuminate").configure(opts)