Remove duplicate test case.

Author: SpacePossum

tests/DifferTest.php

@@ -323,25 +323,6 @@ public function textProvider()
                 "a\nb\nc\nd\ne\nf\ng\nh\ni\nj\nk",
                 "a\np\nc\nd\ne\nf\ng\nh\ni\nw\nk",
             ],
-            [
-                <<<EOF
---- Original
-+++ New
-@@ @@
- a
--b
-+p
-@@ @@
- i
--j
-+w
- k
-
-EOF
-                ,
-                "a\nb\nc\nd\ne\nf\ng\nh\ni\nj\nk",
-                "a\np\nc\nd\ne\nf\ng\nh\ni\nw\nk",
-            ],
         ];
     }