Doomsday Algorithm: Fix leap year check (#12396)

* Fix leap year check

Replace `!=` in `(year % 400) != 0` (line 49) with `==`

Justification: Years that are divisible by 100 (centurian == 100) but not by 400 (year % 400 != 0) are skipped and NOT leap year.

* Update parentheses

Correct the parentheses to make clear the precedence of the conditional check

* Update other/doomsday.py

Co-authored-by: Tianyi Zheng <[email protected]>

---------

Co-authored-by: Tianyi Zheng <[email protected]>

Author: minh-swinburne

other/doomsday.py

@@ -46,7 +46,7 @@ def get_week_day(year: int, month: int, day: int) -> str:
     ) % 7
     day_anchor = (
         DOOMSDAY_NOT_LEAP[month - 1]
-        if (year % 4 != 0) or (centurian == 0 and (year % 400) == 0)
+        if year % 4 != 0 or (centurian == 0 and year % 400 != 0)
         else DOOMSDAY_LEAP[month - 1]
     )
     week_day = (dooms_day + day - day_anchor) % 7