feat: support vim.diagnostic.is_disabled() (#2232)

Co-authored-by: Alexander Courtis <alex@courtis.org>

lua/nvim-tree/diagnostics.lua

@@ -27,6 +27,12 @@ end
 local function from_nvim_lsp()
   local buffer_severity = {}
 
+  local is_disabled = false
+  if vim.fn.has "nvim-0.9" == 1 then
+    is_disabled = vim.diagnostic.is_disabled()
+  end
+
+  if not is_disabled then
     for _, diagnostic in ipairs(vim.diagnostic.get(nil, { severity = M.severity })) do
       local buf = diagnostic.bufnr
       if vim.api.nvim_buf_is_valid(buf) then
@@ -37,6 +43,7 @@ local function from_nvim_lsp()
         end
       end
     end
+  end
 
   return buffer_severity
 end