fix(lsp): check if diagnostics.signs is disabled by user (#2897)

lua/lazyvim/plugins/lsp/init.lua

@@ -120,10 +120,12 @@ return {
 
       -- diagnostics signs
       if vim.fn.has("nvim-0.10.0") == 0 then
-        for severity, icon in pairs(opts.diagnostics.signs.text) do
-          local name = vim.diagnostic.severity[severity]:lower():gsub("^%l", string.upper)
-          name = "DiagnosticSign" .. name
-          vim.fn.sign_define(name, { text = icon, texthl = name, numhl = "" })
+        if type(opts.diagnostics.signs) ~= "boolean" then
+          for severity, icon in pairs(opts.diagnostics.signs.text) do
+            local name = vim.diagnostic.severity[severity]:lower():gsub("^%l", string.upper)
+            name = "DiagnosticSign" .. name
+            vim.fn.sign_define(name, { text = icon, texthl = name, numhl = "" })
+          end
         end
       end