Everywhere: Remove unused includes of AK/Array.h

These instances were detected by searching for files that include
Array.h, but don't match the regex:
\\b(Array(?!\.h>)|iota_array|integer_sequence_generate_array)\\b
These are the three symbols defined by Array.h.

In theory, one might use LibCPP to detect things like this
automatically, but let's do this one step after another.

Userland/Libraries/LibGfx/PNGLoader.cpp

@@ -5,7 +5,6 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <AK/Array.h>
 #include <AK/Debug.h>
 #include <AK/Endian.h>
 #include <AK/Vector.h>