Pyupgrade to Python 3.9 (#4718)

* Pyupgrade to Python 3.9

* updating DIRECTORY.md

Co-authored-by: github-actions <${GITHUB_ACTOR}@users.noreply.github.com>

project_euler/problem_001/sol5.py

@@ -25,7 +25,7 @@ def solution(n: int = 1000) -> int:
     83700
     """
 
-    return sum([i for i in range(n) if i % 3 == 0 or i % 5 == 0])
+    return sum(i for i in range(n) if i % 3 == 0 or i % 5 == 0)
 
 
 if __name__ == "__main__":