Remove duplicate implementation of median of two arrays algorithm (TheAlgorithms#11420)

* Remove duplicate implementation of median of two arrays algorithm

Remove maths/median_of_two_arrays.py because the repo has two
implementations of this algorithm, with
data_structures/arrays/median_two_array.py being the other. Even though
maths/median_of_two_arrays.py is the older implementation, the newer
implementation is better documented, has better error handling, and is
already located in a more appropriate directory.

* updating DIRECTORY.md

---------

Co-authored-by: tianyizheng02 <[email protected]>

Author: tianyizheng02

Diff for: DIRECTORY.md

@@ -661,7 +661,6 @@
   * [Manhattan Distance](maths/manhattan_distance.py)
   * [Matrix Exponentiation](maths/matrix_exponentiation.py)
   * [Max Sum Sliding Window](maths/max_sum_sliding_window.py)
-  * [Median Of Two Arrays](maths/median_of_two_arrays.py)
   * [Minkowski Distance](maths/minkowski_distance.py)
   * [Mobius Function](maths/mobius_function.py)
   * [Modular Division](maths/modular_division.py)