CoreRoundup: Fix post 19 BCMath class namespace cases

Author: Ayesh

source/_posts/2024-10-02-php-core-roundup-19.md

@@ -118,7 +118,7 @@ There are lots of new improvements in this space, including not only the [HTML5
 The BCMath extension in PHP 8.4 now has classes with support for operator overloading support!
 
 ```php
-use BCMath\Number;  
+use BcMath\Number;
 
 $num1 = new Number('22');  
 $num2 = new Number('7');