minor #2820 MagicConstantCasingFixer - Remove defined check (SpacePossum)

This PR was merged into the 2.3 branch.

Discussion
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MagicConstantCasingFixer - Remove defined check

This test is no longer needed on 2.3 and up.

https://3v4l.org/ufX57

Commits
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a5e0b33c Remove defined check.

src/Fixer/Casing/MagicConstantCasingFixer.php

@@ -74,11 +74,8 @@ final class MagicConstantCasingFixer extends AbstractFixer
                 T_METHOD_C => '__METHOD__',
                 T_NS_C => '__NAMESPACE__',
                 CT::T_CLASS_CONSTANT => 'class',
+                T_TRAIT_C => '__TRAIT__',
             ];
-
-            if (defined('T_TRAIT_C')) {
-                $magicConstants[T_TRAIT_C] = '__TRAIT__';
-            }
         }
 
         return $magicConstants;