input: Write a function to sort a dictionary by its values in descending order.
  assert sort_dict({'name':'John', 'age':26, 'salary':3000}) == OrderedDict([('salary', 3000), ('age', 26), ('name', 'John')])
  assert sort_dict({'apple': 2, 'banana': 3, 'cherry': 1}) == OrderedDict([('banana', 3), ('apple', 2), ('cherry', 1)])
  assert sort_dict({'x': 10, 'y': 5, 'z': 15}) == OrderedDict([('z', 15), ('x', 10), ('y', 5)])
output: from collections import OrderedDict
  
  def sort_dict(d):
      return OrderedDict(sorted(d.items(), key=lambda item: item[1], reverse=True))