remove no longer covered tests

Author: staabm

tests/PHPStan/Rules/Arrays/NonexistentOffsetInArrayDimFetchRuleTest.php

@@ -1116,13 +1116,6 @@ public function testPR4385Bis(): void
 		$this->analyse([__DIR__ . '/data/pr-4385-bis.php'], []);
 	}
 
-	public function testBug11276(): void
-	{
-		$this->reportPossiblyNonexistentGeneralArrayOffset = true;
-
-		$this->analyse([__DIR__ . '/data/bug-11276.php'], []);
-	}
-
 	public function testBug12805(): void
 	{
 		$this->reportPossiblyNonexistentGeneralArrayOffset = true;