input: Write a python function to find common languages between two repos.
  assert find_common_languages(["Python", "JavaScript", "HTML"], ["Java", "JavaScript", "CSS"]) == ["JavaScript"]
  assert find_common_languages(["Python", "JavaScript"], ["Java", "JavaScript", "Python"]) == ["Python", "JavaScript"]
  assert find_common_languages(["Python", "JavaScript"], ["Java", "CSS"]) == []
output: def find_common_languages(repo1, repo2):
      return list(set(repo1) & set(repo2))